Weathering is a natural process that breaks down all minerals and rocks and eventually transform them into soil. Without weathering there will be only rocks making plants, animals and life as we know it impossible. Such transformation leaves recognizable marks on the jade surface of burial jades as they underwent the same process similar to other minerals and rocks in a natural environment. Under a 40X magnification, these weathering marks including amorphous silicate, phyllocilicate clay, dissolution of nephrite crystals, and formation of iron oxides and iron hydroxides can be clearly seen as demonstrated on the Han disc magnified below.
Chemical weathering on a Han disc under 20X and 40X magnification..
Han disc surface magnified
Chemical weathering in relation to burial nephrite jade.
Weathering can be divided into physical and chemical weathering. Physical weathering refers to rock breaking apart due to natural forces like exposure to wind and water erosion, climatic heat expansion and contraction, shear force of ice and glacial into exfoliation and so on. Chemical weathering is chemical changes of the minerals in the rocks, induced by surface water, oxygen and carbon dioxide of the atmosphere. The result is the break down of minerals chemically and structurally, releasing cations into the environment, and eventually transform rocks into soil. All rocks contain more than one mineral. All minerals form crystal except when they are in the amorphous phase. A mineral is in amorphous phase when it maintains its chemical composition, but has lost its shape and crystal form. It is often seen in the burial jades as the whitish greyish pasty like material on the jade surface, often mistakenly referred to as calcification. Water is the main medium and the main driving force for chemical weathering. Also important are other variables like a hot, cold, dry or wet climate, the composition of parent minerals with different chemicals and crystal structures, and biological changes bring in by surrounding plants, animals and bacteria in the environment. All these make chemical weathering a very complex process. Chemical weathering is a well studied science in Geology, Geochemistry, Mineralogy, Clay Mineral studies, archeology and Environmental Science. Scientific papers on the subject come from scholars around the world. Changes seen on the burial jade surface so far have eluded explanation which underlies the reason why fake burial jades are so profusely produced. Since most burial jades are nephrite, an amphibole, knowing chemical weathering through these scientific papers on the mafic and felsic rocks; rocks and minerals that are iron rich silicates, provides a path for an authentication solution. Information comes mainly from clay mineral and geology scientific literatures. References are listed at the end of this segment.
The first stage of Chemical weathering and the formation of amorphous silicate.
Chemical weathering can be divided in two stages. Both stages can occur at the same time on the same surface of a mineral rock at various degree due to differences on the surface in drainage, micro pores size, and weakness points on the mineral, namely joints and cracks that can affect the chemical weathering effect. The mineral surface has different points of high energy, points where water flows through or retained. In burial jades high energy points are where the jade surface turns or drops off, the recesses and grooves from lines and cuts, and drill holes on the jade piece. These are areas where most weathering effects take place. Dissolution and leaching is the first stage of weathering. As water comes into contact of the mineral surface, it reacts with the chemical by replacing the cations, and in nephrite, calcium, magnesium and iron, that leach out in a higher ratio than the silicate. The result is the loss of cations and the fibrous nephrite crystals lose their shape and become amorphous. Amorphous silicate has a whitish to greyish color and appears pasty on the jade surface. A protonated surface about 10Å is formed. This is the surface where protonation, in other word the chemical reaction, takes place. Of significance is the protonated surface cannot be cleaned by ultrasound treatment, leaving a permanent mark on the jade surface, and a clue for authentication. (Y. Noack, F. Colin, D. Nahon, J. Delvigne, and L. Michaux. Secondary-Mineral formation during Natural weathering of pyroxene: review and thermodynamic approach. American Journal of Science, Vol. 293, February 1993. P. 111 – 134.) Extensive amorphous silicate formation can be seen on the Zhou (1046 – 256 BCE) jade man shown below. Notice the more heavy concentration of the whitish amorphous silicate beside the raised lines. The lines are positive relieves, formed by cutting down on both sides turning both sides into depressed grooves that retain water. Also when the jade piece was made, it creates fine granules from the cutting and drilling. It is well known in the scientific community that by simply breaking the mineral sample, these fine granules form. ( Mechanism of pyroxene and amphibole weathering – 1, Experimental studies of iron free minerals. Jacques Schotts, Robert A Berner and E Lennert Sjoberg; Geochimica et Comochimica Acta Vol.45, pp. 2123 -2135. 1981) These fine granules when meet with water, go into rapid dissolution skewing the scientific data. To clean them requires washing with a Hydrogen fluoride + Sulfuric acid solution. At the time the jade was made, because of the cutting and drilling, the cut lines and drill holes accumulate a large amount of such granules. These depressions also accumulate water and are high energy points. With more water available, rapid dissolution of these fine granules takes place, resulting in high concentration of the amorphous silicate in these depressions giving them a whitish delineated appearance well known in burial jades . The large amount of fine granules and water accumulation in drill holes also result in large amount of substrate inside the drill hole and formation of unusual secondary mineral products as we should see later. This accumulation of fine granules in the recess areas also can be seen on newly made jade pieces, and the higher concentration of the amorphous silicate in recess areas is greatly imitated by the fake jade makers. Notice also the multiple raised relieves on the surface of the jade man, a phenomena that will be discussed later.
Figure 30. Late Zhou to Qin jade man
More amorphous silicate accumulate on grooves from cutting
Weathering in the surface micro pores, a reason for color change in burial jades.
Weathering occurs on the surface as well as in the micro pore – micro crack system. These micro cracks measure 1µm in width, and as weathering continues lens shape etch pits form parallel to the c axis of the crystal. As more etch pits are formed, they coalesce and the micro pores enlarge widen up to 6µm. Changes on the surface is limited by water penetration, only to 0.05 µm to 0.12 µm, and sets a limit on weathering effect on the surface. Exception to this is in areas of large cracks and joints. These weaknesses allow water to penetrate deeper into the mineral as far as these cracks and joints extend. Clay minerals of the smectite group forms. Because of the size of the micro pores, transformation is at the molecular level, by solid state topotactic mechanism, pesudomorph from nephrite to smectite. Pseudomorph is when a mineral changes into another mineral chemically and physically without changing its shape. Smectite is a clay mineral group with at least 15 members. Their color vary from white to green, dark green close to black, yellow and brown. A yellow clayey plasma is formed. As weathering advances, parent mineral disappears inside the etch pits and voids lined by ferruginous material known as microboxworks form. Boxworks, also call Speleothem, are mineral structure formations when mineral erodes away leaving veins of mother mineral. Boxworks are found often in caves as seen in the picture below from the Elk Room, Wind Cave South Dakota. (Picture from the U S Park Service). As microboxworks
form inside the micropores, they can only seen by electron microscopy. Ferruginous projections called pendants extend from the microboxworks into the void. (MICHAEL ANTHONY VELBEL. WEATHERING OF HORNBLENDE TO FERRUGINOUS PRODUCTS BY A DISSOLUTION-REPRECIPITATION MECHANISM: PETROGRAPHY AND STOICHIOMETRY. Geochimica et Cosmochimica Acta Volume 45, Issue 11, November 1981, Pages 2123-2135.)These microboxwork and pendants exhibit the phenomenon of birefringence, meaning reflective light shine on them can only be seen at a certain angle. Several material exhibit birefringence and crystal is one of them. The specific of birefringence can be used to identify materials especially among minerals. The ferruginous material of the microboxwork are goethite, kaolinite and gibbsite. Smectite can weather into kaolinite. Both are clay minerals and such transformation occurs frequently. Hematite is also frequently found with amphibole weathering depending on the location in the world the parent mineral is from. Hematite is an iron oxide and has color of black, silvery grey, reddish brown and red. Goethite is an iron hydroxide and has color of black, brown, reddish brown and yellow. Kaolinite is a clay mineral with color of white to pale cream and yellow. Smectite has multiple members and they rang from yellow, brown, green and even black, depending on the amount of iron available. These weathering secondary products form inside the micropores and cracks of the nephrite, giving about 0.1 mm of the nephrite surface the color of brown, reddish brown yellow and may even black, the patina color of the burial jades. The Han beast on the left, and the Song frog on the right below have lost their original nephrite color and assume the color of the clay mineral and the iron oxyhydroxide inside their surface micro pores. Chemical weathering is the reason burial jades have such color. Understanding the process is key to identify fakes. When the burial jade pieces are looked at under the microscope obliquely, the color changes from the secondary products can be seen just underneath the surface in the micro pore system, whereas fake jades are dyed from top and remain on the surface.
Figure18. Song frog
Secondary products can be seen spilling out from the micro pores to form pin point dots on the jade surface as on the magnified picture below on the curve surface of the Song frog, more noticeable on the right lower corner of the picture.
Chemical weathering on the nephrite jade surface and formation of ferruginous crust and phyllosilicate clay crystals.
Other than inside the micro pore system, dissolution and leaching also occur on the jade surface resulting in etch pits formation as nephrite crystals dissolve. These pits are shallow due to the limit of water penetration. As in the micropores, when more etch pits are formed, they coalesce and enlarge. Amorphous silicate forms from leaching fills these etch pits. The surface of a Hongshan (4700 -2900 BCE) zoomorphic bird woman shown below demonstrates such effect. Notice that on the upper and lower part of the magnified picture on the right shows formation of phyllosilicate which has a yellowish shinny and grease like color with a reddish tint, an indication iron oxyhydroxide also present as weathering advances into the phyllosilicate / oxyhydroxide stage. Phyllosilicates are clay minerals which are silicates with a sheet like crystal structure. They can be divided into 1:1 or 2:1 clay, meaning, to put it simply, is that their structure can be 2 sheets which the Kaolin group belongs to, or 3 sheets which the smectite group belongs to. Recognizing phyllosillicate is important since they are frequently found on the surface of the burial jades.
Figure 67. Female bird zoomorphic.
Etch pits fill with amorphous silicate
With time and availability of water and oxygen in the enviroment, smectite forms a brown to yellow pasty plasma on the surface. This plasma like material forms a thin filament crust on top. According to a Polish study, this filament measures 20-30 µm, about 0.2 – 0.3 mm. Because it is transparent, the presence of this filament is hard to recognize till you come across some of the jade pieces that were dropped in the past resulting in cracking of this crust. On one Liangzhgu disc (3400-2250 BC) with a diameter of 2 inches, such filament can be demonstrated. Like all Liangzhu discs, this disc is carved only on one side. The underside is flat. On the front, it slopes down abrutly when it comes to the side making a very sharp edge. Under the microscope, cracks can be seen on a whitish yellowish crust filament that covers the whole jade piece. A small piece of the filament is lost, and through this window, the real jade surface can now be seen (see pictures below). Without the cracks, even under the microscope, it is difficult to recognize this crusty filament. The presence of this filament makes the jade surface looks like it has depth, as if it is under water when look through the microscope.
Figure 39. Liangzhu disc with cracks on the crust.
Figure 41. Magnification from figure 40.
Natural nephrite obtain from an alluvial mine of dried up river bed are encased in a rock like crust formed from a process called encrustation pseudomorph. ( Picture below).
As soon as jade pieces were buried inside a tomb, this encrustation pseudomorph process began. This crust takes hundreds of thousand years to develop, at an estimate 50 thousand years for half a cm. The longest burying time for Chinese burial jade is 7000 years. So the changes observed on the burial jade surface comes only from the early stage of this encrustation pseudomorph process as the buried jade forming the crust. Changes in association with this process occur. With available iron, Goethite/Hematite inclusion form inside the filament as seen on the back of this Zhou jade man below. These inclusions on the burial jade surface are superficial, form within the
Zhou kneeling man
smectite plasma filament when free iron from leaching is available. Black Hematite inclusions are also seen in this Han thin dragon below. Black inclusion are more
Han thin dragon
frequently found than red inclusions. Below is a Zhou jade bird with red inclusions within the plasma layer on his crown. Red inclusions are also likely hematite.
With progression of the weathering process, sheet like phyllocate (clay crystal), forms on the surface of the jade. They are more solid looking and less grease like as in the amorphous sillicate. These sheet like structures layer out and can have a reddish tint to solid reddish color indicating the presence of iron as seen on the Liangzhu (3400 – 2250 BC) disc below. Notice the demarcation of the phyosillicate (clay crystal) coming down from the upper left corner on the magnified photograph.
Figure 92. Liangzhu butterfly plaque with two god beasts.
Edge of phyllosilicate coming down from upper left corner
Some crystal form a vein like structure as on this Hongshan (4700 -2900 BC) pig dragon beast shown below. These are phyllosilicate clay crystals form on the surface. The formation of this uneven layer makes the surface appear it has holes on them, as
Vein like phyllosilicate
fake jade makers sand blast the surface to imitate. To appreciate this raised phyllosilicate layer the jade piece needs to be tilted to look at the surface obliquely. Only obliquely that many changes on the surface can be seen. The Xia (2700-1600 BCE) axe shown below has indistinct carvings on the surface easily contributed to aging as the cause of the loss of image clarity. Under the microscope, the reason becomes clear. The whole surface is under cover by a hard crust of clay crystal material. The raised nature of this clay
Crusty Phyllosilicate clay crystal
phyllosilicate crystal crust can be better seen if the axe is look at obliquely as below.
The brownish discoloration seen on the axe is due to iron presentation as black specs of hematite inclusions and silvery metal deposits are seen under the microscope (pictures below). The hair like patch on the right upper corner is not an artifact, as it can be found
in several other burial jade pieces. The Xia bracelet shown below also has such hair like crystal structures.
The exact nature of this structure is unclear. The closest resemblance is the illite crystal, a non expandable clay.
The presence of clay mineral on the surface of burial jades as a secondary product of chemical weathering, results in a well known phenomenon. It has long been known that some of the burial jades process an odor commonly referred to as the ‘tomb odor’. The odor does not come from the tomb, but from the clay produced on the jade. Clay is one of the few minerals that give out an odor. https://www.scientificamerican.com/article/the-odors-of-minerals/ As clay material is formed on the surface of burial jades from chemical weathering, under certain conditions, such clay will give out an odor that jade collectors are so familiar with, and so mistaken with its origin.
Iron oxide mineral crystal formation on jade surface and in drill holes.
The clay phyllosilicate crystals are greyish in color and sheet like. They are however not the only product from chemical weathering as ferruginous materials are also produced from the weathering process, resulting in iron oxide and hydroxide minerals on the burial jade surface. Below is a Liangzhu plaque covered by a red crust, an indication of
iron. ( As a side note, this plaque is very important in Chinese history, as it can easily link the Hongshan and the Liangzhu culture to the Shang culture, integrating the Chinese culture into a truly 7,000 years one linage descence.) Under the microscope the red mineral forms crystal comparable to natural Hematite mineral as seen on a sample
Natural Hematite has silvery metal deposits shown clearly in the middle of the sample above. These type of metal deposits are also frequently found on surface of burial jades. The Liangzhu bead below shows such deposit on the upper right of the magnified
Liangzhu bead with metal deposit
Metal deposit on upper right
photo. These metal deposits appear as droplets, and they all show the birefringence effect, seen only at a certain angle, making finding them a difficult task at time. Below is a Zhou comb that also has the metal droplets on its surface, seen at the center of the magnified view below .
Metal droplets in association with the Hematite formation is not the only metallic finding on the burial jade surface. Small pin point like metallic shine with a bright golden yellow color are often seen on Han or older pieces. Unlike the droplets, which appear at random, these metal shines always appear in a line, be it curve or straight, and like the droplets, they also exhibit the birefringence effect. The presence of such lines can be demonstrated on the Hongshan beast below, seen in the middle of the magnified view.
Hongshan beast with metallic line
Tiny metallic points forming a line.
This type of metallic line formation can also seen on the Han beast below. The exact
Han beast with metallic line.
nature of these metallic points line is uncertain. However since they always appear in a line, they probably are related to the cleavages of the nephrite jade.
As weathering products form on the jade surface they crystalize. Within the drill holes due to the presence of large amount of fine granules from the drilling, and the larger amount of water available, result in a large amount of ferruginous substrate inside a cave like space, and needle like Hematite crystal forms. Below is a Hongshan bird with a worm on its head. Within the drill hole, needle Hematite crystal forms. This is not the
only Hongshan piece that has such crystal formation, indicating such crystals can be found in many genuine Hongshan pieces. Other crystal formations on the surface are more difficult to understand, like on this Hongshan birdman below.
Hongshan bird man
Unknown crystal formation
Effect of cleaning on jade surface.
Chinese jade collectors have always divided collectable jades into unearthed jades (出土玉), and jades from hereditary (傳世玉), It is difficult to understand why should there be such a division and what puts them apart, until the jades are looked at under the microscope. The unearthed ones retain all the markings from weathering, whereas the hereditary ones were cleaned by previous owners. What can be cleaned on the surface are the clay and ferruginous crust. Once this crust is removed, the protonated layer where the chemical reaction of the weathering process took place is exposed. The protonated layer cannot be clean even with ultra sound cleaning. Also the patina color of the burial jade, caused by the clay and ferruginous material produced inside the surface micro pores cannot be cleaned. Below is a Xia mask that has been cleaned in the
Xia mask previously cleaned with removal of the clay and ferruginous crust. The protonated layer and the patina color caused by the clay and ferruginous material in the surface micro pores cannot be cleaned.
Reminant of the crust can be seen on the lip and the left side of the nose.
past with removal of the clay and ferruginous crust. The patina which results from the clay and ferruginous material inside the surface micro pores remains unchanged. Also note the protonated layer on the nose. In spite of the cleaning, remanents of the crust are frequently found, left behind in recess or obscure areas, as seen on the left side of the nose and the lip of the mask. Remanent of the crust is more pronounce on a thoroughly cleaned Han beast below, left behind notably on its left tail. Removing the crust also
Remanent of crust magnified.
Remanent of crust on left tail
exposes other markings from weathering as seen on the Han cicada below. Notice the loss of mineral crystal material on its right side of its head, both eyes and back, from the leaching and dissolution stage of weathering, resulting in shallow etch pits as if a small piece of the skin was removed, and formation of the protonated layer where the chemical reaction took place (on the magnified view).
Han cicada with loss of crystal material from the leaching and dissolution stage.
Loss of mineral from leaching and dissolution with frmation of etch pits and protonated layer.
How much burial jades can be cleaned, and whether they can be returned to their original nephrite luster is controversial. The National Museum in Beijing China has done just that showing several of their burial jades pieces returned to their original nephrite color. This promptly leads to Western archeological communities criticism, that such feat is impossible and suspicion that these are newly made fakes. The patina color change is due to the chemical weathering effects on the surface of the burial jade. Due to the limit of water penetration, such effect only limits to the surface 0.1 mm or so. It is therefore possible to grind off this topical 0.1 mm and the jade should return to its original nephrite color. However by doing so will also eliminate much of the details of the surface carving. The value of the burial jades lies not in the nephrite, but in the art and spirit of the carving thatreflects the thinking and culture of the carvers, people of the period of time. Any damage done to the carving will result in great loss. Further more, markings left from the chemical weathering are the strongest proof, and may be the only proof that the jade piece is authentic. Removing these markings by grinding the surface will render the piece losing all its identity, and hence no difference from a piece made nowadays.
Raised relief on nephrite jade artifact, what it is and confirmation of chemical weathering on Nephrite jades.
The only scientific article exploring burial nephrite jade with regard to geologic mineral changes is “Raised relief on nephrite jade artifacts: observations, explanations and implications. Journal of Arcaeological Science, 40 (2013) 943-954.” by Frederick A. Cook. This is truly an excellent pioneer work in this field that deserves all the respects given to a true insight into the chemical weathering on burial jades. In this article Professor Cook investigates the notion that raised relief can be found on the surface of burial nephrite jades, and the presence of such relief if proven genuine, can be used to confirm the authenticity of the artifact. The article provides confirmation to observations already discussed in this writing. However it also posts other questions that are worth looking into. The article divides the raise relief into two categories. One is a raised crystal, often single, but can be in groups. The other is a patch or areas higher and above the observed jade surface. These patches contain no raised crystal as in the other group, but are made up with fibrous normal nephrite crystals. Judging from the pictures of the artifact specimens in the article, one can easily see that all artifactsexcept number 4 the Neolithic Bi disc, and number 6 the circular bowl with a stand, the surface has been previously cleaned. (One side note is that judging from the bird headed hunter on the circular bowl, as compared to the bird headed people on the Han disc posted at the beginning of this chemical weathering writing, the circular bowl should be a Han piece and not Tang.) The patches being referred to as raised relief appear to be the remnant of the clay phyllosilicate crust left behind after the previous cleaning. The crust is above the surface, but certainly is not raised, a reason why underneath the patch normal fibrous nephrite crystals are found. Of some interest is specimen number 4, the Neolithic Bi Disc. This disc was not cleaned, and phyllosilicate clay on the surface is obvious, easily seen especially on the magnified view. Part of the disc was under cover from another disc. As a result less water was available on the part of the disc under cover, and that part of the disc has far less weathering effect, and hence far less clay phyllosilicate on the covered part of the disc surface, demonstrating the importance of water in chemical weathering.
Of the two groups, group one has the true raised relief, jades with a crystal on and above the nephrite jade surface. Raised relief are not frequently found, only may be on 5% of the burial jades. When it occurs, they usually are multiple, as seen on the picture of specimen 6 in the Raised Relief article, the circular bowl with a stand. Also by scrolling back to the top third figure of this writing, the Zhou jade man, one can see the raised relief on the surface are also multiple. Multiplicity of the raised relief is also the case on the three Hongshan jade pieces shown below. The first one is a squatting monster man
Multiple raised relief.
Figure32. Hongshan zoomorphic with raised relief.
with its raised relief magnified shown below. Notice the similarity of the raised relief on the monster man and those found on the circular bowl on figure 6.
Figure33. Magnified zoomorphic surface.
The next is a C-dragon with raised relief as shown below. When comparing the raised relief on the C-dragon and the monster man, one should put into consideration that the C- dragon measures 15 cm in length, whereas the monster man is only 4 cm in height. The size of the raised relief on the two pieces may be comparable. There are however differences between the two types of raised relieves. Those on the c-dragon are black
with silvery metal deposit on many of them, whereas those on the monster man are lighter in color with no metal deposit found. The third raised relief example is on a squatting beast shown below. The raised relief on the beast are also different from the
Figure 37. Hongshan zoomorphic pseudomorph
raised relief on the other two Hongshan pieces. Unlike those on the other two that are crystals in a cluster, those on the squatting beast are individual crystals. They also differ in texture, smooth with a Smokey semi transparent color and no metal deposit, a resemblance to Smoke Quartz. The differences between the raised relief on all three pieces indicate that they are probably different mineral crystals. There may be more than one kind of crystal forming raised relief.
The raised relief was thoroughly investigated scientifically in the article. Thin slides made from specimen 6, the bowl with stand, were chosen for petrographic microscopy and electron microprobe examination and analysis. The raised relief selected is a single pyroxene crystal, a diopside on the jade surface. There are other diopside crystals found, all at or near the surface of the bowl. The assumption is that these pyroxene crystals are formed during the nephrite metamorphic formation. As the nephrite was pushed from the crust of the earth to the surface, hydrothermal alteration continues the alteration of the diopside to tremolite. Since the pyroxene was present during metamorphism when the nephrite was formed, it has to be inside the nephrite before the jade piece was carved. If such is the case, the diopside should be found any where inside the nephrite, and should not only be at or near the surface. One interesting finding is that the red brown color on the surface of the bowl is limited to 0.1-0.2 mm of the surface, a finding consistent with the changes result from chemical weathering inside the surface micro pores due to the limit of water penetration as already discussed.
The raised relief is a large crystal, in this case a diopside, intersecting the surface, and surrounded by fibrous nephrite crystals. The nephrite crystals are in two forms, a coarse altered form found immediate to the diopside crystal, which in turn are surrounded by the more fine fibrous tremolite crystals. It is felt that the diopside crystal is altering into tremolite crystals, as in hydrothermal alteration, resulting in the tremolite fibrous mass. The diopside crystal shows twinning with coarse tremolite veins in between. Of more revealing are the electron microprobe analysis. (figure 11-12, table 2) Other than the diopside crystal and the fine and coarse tremolite crystals, hydrous phase material and chlorite are found. Because the hydrous phase materials are high in aluminum and magnesium it is determined that the hydrous materials are clay minerals, and chlorite will eventually alter into it. Of interest to note is that the altered tremolite, the hydrous phase material, and the chlorite are all high in iron oxide (FeO). The conclusion is that the clay is expansive. The expansion of the clay increases the volume resulting the diopside being pushed to the jade surface forming the raised relief. This conclusion is reasonable. However it does post some questions. The pushing due to the expansion of the clay is mechanical, and not gravitational dependent. Further more when the jades were buried, they were placed face up or down or side way. So the diopside crystal can be pushed in any direction and not necessary towards the surface. This assumption cannot explain why all the raised relief are at the surface of the jade. Also a well known fact about the expansive clay is that found around building foundations. The expansion can cause cracking of the foundations leading to crumbling of the building. Clay expansion within the jade should create large cracks around the diopside crystal. Micro cracks sre found in the round bowl specimen. Micro cracks are known to form during chemical weathering. The diameter of the micro pores on the nephrite are 1µ – 2 µ. Leaching and dissolution during chemical weathering leads to enlargement of the micro pores to 5µ and formation of micro cracks. Expansion and pushing should create much larger cracks, and with thousands of years of burial and pushing, may even lead to dislodgment of the diopside leaving behind a void. Such are not found leaving more questions to the assumption of clay expansion theory.
Excellent studies were done on the bowl with a stand specimen. Clearly the nephrite crystals around the diopside are altering. The assumption here is the diopside is altering into nephrite as in the metamorphic process under a hydrothermal effect. Hydrothermal activity in China concentrates in the south west. The rest of the country where the nephrite jades were buried has minimal hydrothermal activity especially in the north east where the Hongshan jades were buried, making encountering hydrothermal fluid highly unlikely. There is no doubt however that the nephrite crystals around the diopside are under going alternation. One other explanation is that the raised relief is a pseudomorph process. Pseudomorph takes place in surface temperature and pressure and it can also exhibit twinning. The tremolite crystals are altering into diopside. In other word all raised relief are alternation pseudomorphs after Tremolite. Pseudomorph alteration also explains why all raised relief are found at the surface. Two examples of pseudomorphs are shown below for comparison to the burial jade raise relief, a limonite pseudomorph after Siderite,
and a copper pseudomorph after aragonite. (picture from James St John, Wikipedia.) Regardless of what the raised relieves are, its presence should confirm the authenticity of the burial jade.
The article studies confirm nephrite chemical weathering secondary products. Chlorite has been reported, and it eventually alters into clay minerals Smectite and Kaolinite. The secondary products have also been described as ferruginous because of the high iron content. Iron secondary minerals are iron oxide Hematite, and iron hydroxide Goethite. MICHAEL ANTHONY VELBEL. WEATHERING OF HORNBLENDE TO FERRUGINOUS PRODUCTS BY A DISSOLUTION-REPRECIPITATION MECHANISM: PETROGRAPHY AND STOICHIOMETRY. Geochimica et Cosmochimica Acta Volume 45, Issue 11, November 1981, Pages 2123-2135.
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As the world’s oldest continuous civilization, China’s history stretches back more than 5,000 years to the Neolithic time. Recent advances in Archeologic Science in China have also shone a light on the culture as it has never. As a civilization, jade has always played an important part ever since the dawn of Chinese history, revered as mysterious and precious. Carvers often express their religious beliefs in an artistic form, to adorn kings, queens, nobles, and influential leaders of the society and buried with them at their death. Since jadeite only came into China after the Ming Dynasty, Jade in China before the Ming Dynasty was always nephrite. As a mineral, nephrite can last thousands of years and are better preserved as an artifact than wood and may even better than clay wares and metal. To look into the society of the time, especially into their religious beliefs, is no better than through the buried nephrite. However, buried nephrite of Chinese antiquity is notorious with rampant forgeries to the point that fakes and genuine buried nephrites may not be distinguishable. Unfortunately, even the Chinese government may not be helpful in this regard. On the internet, imageries are near 100% fake jades. Self-proclaimed reference books post fake jade photos. Of the three Chinese Neolithic jade cultures, Hongshan (4700-2900 BC), Lingjiatan (3750-3000 BC), and Liangzhu (3400-2250 BC), Hongshan should be considered the earliest jade culture. But Hongshan jade is also the most chaotic. With so many fake Hongshan jade flooded the market, ironically, even the forgery carvers themselves may not have seen an authentic piece of Hongshan jade. As a result, fake Hongshan jade may not be a copy of the original, but merely something out of the fake jade carver’s imaginary. The tragic consequence is people, including the Chinese themselves, are unable to see the real face of the Chinese civilization.
The Hongshan archeology sites were discovered in the early 1920s. Between 1983 and 2003, the Liaoning Institute of Cultural Relics and Archaeology undertook a series of extensive excavations of the sites. Other than many significant archeologic artifacts, 100 pieces of jade were obtained. These 100 pieces also include those damaged and incomplete. Some scholars estimate that 90% of the jade artifacts were removed illegally before the official excavations. But if you take 10% is 100 pieces, the total number of Hongshan jade is only 1000. Compare that with the hundreds of thousands and may even be a million fake Hongshan jade on the market today, one can easily see genuine Hongshan jade is a rarity. Hongshan culture, despite the fact being Neolithic, obtained high artistic levels in their jade carvings, even in today’s standard. Replacing such artistic achievement by the distasteful jade carvings of today distort not only the origin of the Chinese culture but also disrespectful for the cultural heritage of their ancestors.
Because of the rampant forgery, it is imperative that the Hongshan jade pieces presented here must be genuine, and the proof of such has to be in the authentication. Traditional authentication is comparing the jade piece to a known unearth relic. However, because the Hongshan jade obtained from the excavation is only 10%, it cannot be representative, and comparing the jade piece to the excavated ones is meaningless. Authentication must rely on the recognition of tool marks and color change on the jade surface. It is especially important to the color change that results from the weathering process of the mineral nephrite (see the article Chemical Weathering on this web site). The method of authentication will be presented. Only with some certainty that the jade pieces are genuine, that looking through them into the art and beliefs of the Hongshan society 5,000 years ago can make sense.
Hongshan culture (4700BCE-2900BCE) was one of the Neolithic cultures in North-Eastern China, stretching north from southwestern Inner Mongolia, south to northern Heibei, and East to Liaoning. The name that applies to this vast area includes over one thousand village archeology sites of the same culture. In 1908 the Japanese archeologist Ryuzo Torii first discovered the site. Limited excavations were carried out by French and Japanese areological teams in the 1930s. It was not until 1983 to 2003 that the Liaoning Institute of Cultural Relics and Archaeology undertook a series of extensive excavations. It becomes known that the Hongshan culture was based on Xinglongwa Culture and Zhaobaogou Culture and was the most advanced culture in northeast China of the time, advanced from hunting and gathering into farming communities. Stone tools were used for hunting, fishing, farming, pottery making, as well as for jade carving. The most significant finds were a goddess temple with a life-size painted head of the goddess, round sacrificial altars, and square stone tombs. Within the graves, a variety of jade articles were found as sole buried objects with no other artifacts such as pottery or stone tools. Jade, as the only buried objects, indicated that they were objects of religious belief rather than objects of earthly value. Hongshan produced jade objects of varies form. Most notably were the C-dragons, pig dragons, beast in human form, animals, insects, and birds, with the more abstract form the hooked cloud plaque. Despite being a Neolithic culture, Hongshan produced many of the jade pieces with high artistic levels comparable even in today’s standard.
Hongshan culture had developed highly sophisticated pottery made with metal molds from fine red clay decorated with black geometric patterns. Pottery was mainly bowls, plates, pots, and cups for daily use. Among the pottery was a bottomless round tube that could not carry food and drinks, making it an unlikely utensil object (Figure 1). These tubes were found in large tombs lining the sides of the grave. The
geometric black paint pattern on the tubs was also unique, unlike those on other pottery, indicating that these tubes most likely had a religious function. Six female clay figurines in pregnancy were also found, linking the culture to fertility worship (Figure 2). Such
religious beliefs in pregnancy and the bottomless tube, also are reflected firmly in many Hongshan jade pieces, as we shall see later.
Authentication of the Hongshan Jade
The most notable and well known about Hongshan culture is its jade, with the C-dragon and the pig dragon as the most representative. Others are animal forms of beast, birds, tortoise, the horseshoes, and the hook cloud plaques. Elizabeth Childs-Johnson’s paper “Jades of the Hongshan culture: the dragon and fertility cult worship.” https://www.persee.fr/doc/arasi_0004-3958_1991_num_46_1_1303 listed all the jade pieces from the official excavation with drawings and can be regarded as the most reliable reference source in the study of the Hongshan jades. These jades have a beauty of its own and can truly represent the culture on its own right. Unfortunately, because 90% of the Hongshan jades were lost before the excavation, the excavated jades can only give a glimpse of its true nature.
Most of the Hongshan jades are small, ranging from 3 cm to 8cm in length. Larger pieces can be as long as 18cm, with some hook cloud plaque as long as 28cm. The size of the Hongshan jades is similar to Chinese jades from other periods before the Qing Dynasty (1644- 1912 AD). To understand this size uniformity, one has first to look at Hetian. Jade rough or raw jade has been coming from Hetian since the Shang Dynasty (1600 BCE – 1046 BCE). Hetian jades are from pebbles in the stream and small boulders from riverbeds. These pebbles and boulders are small in size, and hence the size of the jade rough limited the size of the jade pieces carved. It was not until the early Qing Dynasty that jade veins in the mountain were mined. For sure, Hongshan jade rough did not come from Hetian. It is also highly unlikely that Hongshan people were able to mine jade veins in the mountain. The size of the Hongshan jade pieces indicates that the source of the jade rough should be similar and was also from streams and riverbeds. For such reason, any Hongshan jade bigger than 30cm should be highly suspicious for modern day forgery. Traditionally comparing the shape and style of the carving of a jade piece to a known unearthed piece is the first step of authentication. However, since the majority of the Hongshan jades are lost, the unearth pieces may not represent the culture. Authentication here will look at tool marks and color change on the jade surface. Such color change is the result of secondary products formation from chemical weathering when the jade was buried.
Tool marks identification
The most important thing about tool marks on the Hongshan jades is not the tool marks, but rather the lack of it. In 2004 the British Museum published a paper “The identification of carving techniques on Chinese jade, Margaret Sax, Nigel D. Meek, Carol Michaelson, Andrew P. Middleton; Journal of Archaeological Science 31 (2004) 1413-1428”. The authors examined six pieces of Chinese jades that belonged to the British Museum for carving tool marks. Positive molds were made for any tool marks found under a microscope. The molds were then examined under an electron microscope to determine the carving technique of the jades. Of the six pieces, one was a Hongshan bird. After a thorough examination, the only tool mark found on the Hongshan bird was line cutting marks inside the drill holes at the top of where the two holes met. The lack of tool marks on the surface probably was due to the polishing at the time of the carving and the subsequent weathering effects on the jade surface, as the authors explained. If we look at the Hongshan jade, the technique employed by the Hongshan jade carvers was principally grinding and polishing. To make the feature to be delineated to stand out, the material around the feature was ground down to make shallow and wide grooves, as seen on the facial feature of an eye and nose (Figure 3 and Figure 6), and around hand and arm (Figure 4). Thin carve in lines was seldom used except on pig dragons, especially on the larger ones. Such a technique of grinding and polishing was done with
abrasive, which results in a smooth surface with no tool marks. A good example is the bird figure in figure 6. Another carving technique used was line cutting, also with the help of abrasive, as demonstrated on the mouth (Fig. 5). The cutting on the mouth is straight, but the flexibility of the line results in the floor of the mouth not leveled.
Drill holes are significant features of the Hongshan jades. Most of the smaller pieces, 8 cm or smaller, have drill holes. Larger pieces bigger than 14 cm, as a rule, do not have drill holes. Such finding means that smaller pieces were used as hanging pieces to adorn the body, whereas larger pieces were statues. There are two types of drill holes. One type is direct through and through round holes from one side to the other, as seen on the bird behind the eyes (Figure 6). The other type is a two communicating holes
diagonally drilled from the same surface (Figure 7). These types of drill holes are often
referred to as the ox nose holes and are exclusively associated with the Hongshan jades. The resemblance to an ox nose can be easily seen with the extension of the part outside of the opening of the hole. Drilling such holes requires the drill placed at an angle on the jade surface. The position of the drill is the cause of the hole widening into an ox nose shape. In many of these diagonally drilled holes, like those in figure 7, such assertion is accurate. But in some ox nose holes, like the one on the C-dragons and hook cloud plaques, may have a different reason. These holes are not diagonally drilled and the holes are not on the same surface. These are through and through holes from one side to the other side, and yet they all have the extension ox nose part (Figures 8a, b, figure 9a, b, and figure10). Drilling a through and through hole, the drill is placed at ninety degrees
to the jade surface. The placement of the drill in this position will not cause the formation of the ox nose part (see the round through and through hole in figure 6). The ox nose part of the holes on the C-dragon and the hook cloud plaque must be an add on to the through and through holes, placed intentionally. Notice the ox nose parts are also pointing at different directions. On figure 8a, b, C-dragon, the directions are upward and downward. On the C-dragon in figure 9a, b, the directions are forward and backward. On
figure 10, hook cloud plaque, the ox nose parts are pointing upward to either side. Notice
the pig dragon on the back of the C-dragon in figure 8a, b, the round hole on it does not have the ox nose part. The ox nose parts are only on the C-dragon. A C-dragon and a hook cloud plaque without the ox nose on the round through and through holes should be highly suspicious for modern day forgery.
The Hongshan culture eventually disappeared from Chinese history, and with it the same surface diagonally drilled holes. All subsequent hanging holes on Chinese jades were the round through and through type. It was not until the middle of the 20th century when mass-produced fake Hongshan jades came into the market that these same surface diagonally drilled holes returned to China. The same surface diagonally drilled holes do not necessarily have the ox nose part (Figure 11). This type of drilled holes was
used extensively on the netsukes in Japan (figure 12a and b), before they came back to
China. No one knows when and by whom the netsukes were created. The earliest netsukes are of the late eighteenth century. The fact that there is no drill hole in the world drilled on the same surface other than on Hongshan jades, raises the question of the relationship between the netsuke and the Hongshan jades. The Japanese netsukes have a high resemblance to the small size Hongshan jades. Adding to that the circumstance around the Hongshan site discovery was also interesting. The Hongshan archeologic site was first discovered in 1908 by the Japanese archeologist Ryuzio Torii. He was at that time a teacher in Mongolia for the royal family. For no known reason, Ryuzio Torii went hundreds of miles straight to the Hongshan site, without searching as if he knew where the site was and became the first person who discovered the Hongshan site. No doubt netsukes have the origin and root in Japan. But evidence points to a likely scenario that some Hongshan jades came into Japan during the late eighteen century and greatly influenced the netsukes development.
Not all Hongshan jades are lack of tool mark. The most apparent drill mark left behind a Hongshan jade is on this drill hole (Figure 13). The hole is not thoroughly
through and is on a 17.5 cm X 15.75 cm hook cloud plaque behind the face of a beast (figure 14). On the side of the drill hole are circular, irregular, and shallow marks, a sign
that it was drilled with a hand drill with abrasive, as in contrast to marks made with modern drills that are deep and regular, similar to marks left behind from a screw. Also, notice that the edge of the bottom of the drill hole is deeper than the center. This indicates that the drilling was done with a center hollow drill, and hence the pressure was applied only on the edge at the part of the drill where it was solid. Abrasive was used and because only the solid part of the drill was effective, drilling was only at the edge of the hole, at the solid part of the drill. As the drill went down the side of the drill hole, the hollow drill left a core in the center. The core was then removed by chipping, and the bottom smoothed. Speculation has been that the hollow drill was a piece of bamboo. But the softness of the bamboo makes it unlikely to be the drill for the much harder nephrite surface. The diameter of many of these drill holes are small, often 3 – 4 mm. To drill such a small size hole, a piece of bamboo of similar diameter must be used. Bamboo of this size will not be able to withstand the constant twisting during the drilling. The more likely candidate for such a drill is a piece of an animal long bone, like an arm or leg bone. Bone has a hardness of 5 on the Mohs scale, like that of iron, making it a much suitable tool than bamboo. The readily available bone is also known used as a tool since the Paleolithic time in China.
It has long known that Long drill holes in Neolithic China tend to taper to the center and are drilled from both sides. The reason for such a tapering effect is because only one piece of bone was used as a drill for half of the hole. During the drilling, friction and rubbing of the drill against the side wall decreased the diameter of the bone drill as it went down. As a result, the hole tapered towards the center. Because all animal long bones are hollow in the center, the drilling creates a central core in the center of the drill hole. The small diameter of the drill hole requires a small animal bone with small long bone diameter. Since the diameter of the bone was relative to the length and as the drill hole tends to have a small diameter, the piece of bone used also tends to be short. For the longer drill hole, it was necessary to drill from the other side. The same tapering effect to the center will result. When the two sides met in the middle, the core was released and dropped out. Due to the slight imperfection of alignment, it always left behind a small notch in the middle of the drill hole. As animal long bones came in pair, a similar diameter size and length bone drill could be easily obtained for drilling from the other side. Drilling in such a way was the most efficient with the least effort.
Identifying modern tool marks on the jade surface is one way to identify forgeries. Recognizing toll marks of the period, together with recognizing changes on the jade surface resulting from chemical weathering, are essential to separate the genuine from the fake buried nephrite.
Chemical weathering effects
For centuries people know that Chines buried nephrites underwent a color change from its original natural state to a greyish, brownish, reddish, and may even be blackish discoloration. Such changes are taken for granted, and no one knows why, and no one has asked any question of what causes such a change. However, simulating such a change of color on the nephrite surface is the principle way to make forgeries. Therefore, recognizing the actual natural color change and knowing the reason for such change on the jade surface is crucial to identify the fakes from the genuine. The buried nephrite color change comes from the secondary products produced from the chemical weathering process when the nephrites were buried. All minerals and rocks undergo the weathering process in a natural environment. There are two types of weathering, physical weathering from wind and water erosion, expansion and contraction from frost and snow, and invasion from animal and plant when rocks and minerals are above ground. Chemical Weathering is a chemical process of the interaction of minerals and water when they encounter underground. Chinese nephrites were buried in graves and tombs, some like Hongshan jades for over five thousand years. Secondary products from the weathering process form inside the micropores and microcracks of the nephrite. Because there is a limit to how deep water can penetrate the nephrite surface, as more secondary products are formed with time, the limitation of how deep it can go into the nephrite forces the secondary products overflow from the micropores and microcracks onto the jade surface. As the secondary chemical products spill onto the surface, they form crystals with specific color different from the nephrite. Because all the secondary products have their own color, the crystallization of such products on the jade surface, together with the secondary products form inside the micropore and microcracks of the nephrite, is the reason for the color change on the buried nephrite. The changes in the nephrite only occur on the topical 0.1 – 0.2 mm. The limitation of the changes to only such a thin layer is the reason why using spectroscopy and x-ray diffraction in the laboratory to test the buried nephrite only gives the answer that it is nephrite and does not verify the chemical weathering effect on the surface. The chemical weathering effect can be easily observed under a 40X magnification stereo microscope. It must be emphasized that none of these changes has been confirmed scientifically. All are based on the correlation between observation and reference from Chemical Weathering literature. (See the Nephrite Fundamental and Chemical Weathering Blogs on this site). Hopefully scientific confirmations will eventually come. But the observation of the changes is accurate enough to identify genuine buried nephrites from forgeries as we look into the Hongshan jades from this perspective.
Nephrite can be considered as a mineral even though it composes of Actinolite and Tremolite. Chemically It is a calcium, magnesium, and iron-rich silicate belonging to the amphibole group and has a needle-like fibrous crystal structure (Figure 15). Iron is what gives color to Nephrite. Tremolite is rich in magnesium and therefore
white, and Actinolite is rich in iron and therefore has the color of green, yellow, brown, and even black. The proportion of Tremolite and Actinolite in Nephrite determines the color of the nephrite. Today any Nephrite containing more than eighty percent of Tremolite is considered Hetian mutton fat jade regardless of its origin. Within the nephrite, there are micropores and micro-cracks seen only under an electron microscope (Figure 16). Such micropores and micro-cracks play a crucial role in
Chemical Weathering and color change on the jade surface, as we shall see.
Igneous, metamorphic, and sedimentary rocks form the crust of the earth. Igneous and metamorphic rocks form in the earth mantle under high temperature and pressure. As they move into the low temperature and low-pressure crust, they become unstable. Physical weathering first breaks up rocks into smaller boulders and pebbles. Chemical weathering eventually reduces them into more stable minerals, releasing cations, forming clay. Clay minerals, together with sand, hummus, and water, become soil. Without weathering there will be no soil and without soil, there will be no plant and no animal life. Life as we know it will not be possible, emphasizing the importance of weathering in nature. Water is the most crucial element of weathering. As a result, weathering is a slower process in cold and arid areas and less pronounced than in wet and hot regions. Within the same area, weathering effects can be different on the same rocks and minerals due to differences in water flow, and the surrounding environment of the rocks. Even on the same pebble, varying degrees of weathering can be observed in different parts due to the influence of water flow. All of these are important to remember when observing the chemical weathering effect on the buried nephrite. The differences in location of the buried site, over hundreds or thousands of years in the change of water flow, periods of wet and dry weather change, and shifting of soil can all influence the weathering effect observed on the buried nephrites, and are important to consider when looking at the weathering effect.
Dissolution and leeching are the initial steps of Chemical Weathering. In nephrite, calcium, magnesium, and potassium leach out, flowed with water, and eventually lost to the sea, contributing to the salinity of the seawater. Silicate also leeches out, but in proportion to a lesser extent. The loss of cations leads to crystal structure change and amorphous silicate forms. Often the whitish-grey amorphous silicate appears on the nephrite surface is mistaken as calcium (Figure 17). On many fake buried
nephrites white powder is randomly placed on the surface to simulate the amorphous silicate. Notice in figure 17, the distribution of the amorphous silicate has a pattern. During the jade carving, a large amount of fine nephrite granules was produced and left around the cut lines, in groves, depressions, and drill holes, places where polishing was unlikely to reach. Such areas also tended to retain water. The dissolution of these fine granules into amorphous silicate resulted in an appearance as if the amorphous silicate was outlining the lines and groves, as shown in figure 17. It is also the reason why large amounts of such whitish-grey amorphous silicate are often found inside drill holes obscuring tool marks.
Leeching and dissolution enlarge micropores and microcracks. Hydrolysis and oxidation also take place, and secondary products form. Nephrite, as a member of the amphibole group, forms clay minerals Smectite and Kaolinite, and iron oxides Hematite and Goethite. The clay minerals have a white to greyish, yellowish color. The iron oxides Hematite has a deep red to brownish red color but also can be dark grey. The other iron oxide Goethite can be yellow, red, deep brown, and can also be black. The formation of the secondary products on the jade surface is the basis of color change on buried nephrites. As hydrolysis and oxidation require water, water determines all changes seen on the nephrite, and since the penetration of water into the nephrite surface is limited, only 100 to 150 angstroms from scientific studies, changes are only limited to an extremely thin topical layer. Secondary products first form in the micropores and microcracks as a ferruginous gel-like substance. Depending on the secondary products formed, the buried nephrite color starts to change into the secondary product color in the micropores and microcracks. At first the nephrite loses its luster, and as more products form, the color begins to change as in the Song frog in figure 18. Due to the lack of water penetration, as more secondary products formed,
micropores and microcracks behave as they are plugged. Continue formation of the secondary products results in the spilling of the ferruginous gel onto the surface of the nephrite forming a crust, and eventually crystallize. Similar changes also are seen on the nephrite pebbles found in streams. Many of the secondary products developed on the surface may have washed away by the water stream. But iron oxides Hematite and Goethite can crystalize, and a reddish, yellowish skin can form on the surface together with greyish clay phyllosilicate (Figure 19).
Throughout Chinese history, collectors consider there are two types of buried nephrites, those newly unearthed, and those in collectors’ hands for generations. Those newly unearthed retain all the chemical weathering effect. Those that have been in collector’s hand underwent surface cleansing. Chinese collectors habitually rub and may even scrap the jade surface to clean what they consider dirt in an attempt to return the jade to its pre buried color. Many hundreds of years of such rubbing and cleaning results in the removal of the crust made of secondary products, exposing the jade surface with the secondary products still in the micropores and microcracks. Figure 20 is a Han (221 -206 BC) beast that has been in collectors’ hands for hundreds of years. Frequent
rubbing, scraping, and cleaning results in the removal of the secondary products, exposing the jade surface. Figure 21 shows the Han beast surface under a 40X stereotactic microscope. During the dissolution and leaching phase, due to the loss of substance, the surface micropores enlarge, and eventually, they coalesce forming an elongated shallow pit as if the jade has lost a small piece of skin as shown in figure 21. A brownish protonation layer where the chemical reaction took place, form at the bottom
of the pit. The protonation layer is only a few atoms thick and cannot be removed with ultrasound cleaning. The red arrows point to two thin silvery lines with a metallic shine. Such silvery lines are frequently seen on the buried nephrite surface. Most of them are in single file straight lines, with some seen at the edge of the crust edge. Because the angle of reflection of such lines is not ninety degrees, to see these lines, one must hold the jade piece to put it into the microscope focus, tilting the surface to look at the surface at different angles. The nature of these metallic lines is not clear. But in some, they seem to be formed by tiny metallic granules. Looking under the microscope obliquely by tilting the jade is also the best way to appreciate the thickness of the crust and the crystal formation of the secondary products on the jade surface. Notice there are phyllosilicate crystals of the clay mineral remain on the right side of figure 21, despite hundreds of years of rubbing and cleaning by many generations of owners.
Most of the metallic lines are silver. Less often seen are the golden yellow metallic lines. Figure 22 is a Hongshan zoomorphic. Under the microscope (Figure 23a),
the edge of a semitransparent, smooth ferruginous crust can be seen at the center with golden-yellow granules forming a line (in red circle). Below the red circle are phyllosilicate crystals of clay mineral formation. The greyish-white material has a look of irregular thicken plaque made up of sheet-like crystal of the phyllosilicate. All of these are on top of a darkish red iron oxide that encases the whole beast zoomorphic, giving the beast a reddish look (Figure 23b). In figure 23b under a 24X stereo microscope, at an oblique view, the secondary product of iron oxide, likely Hematite, can be view covering
the surface of the zoomorphic beast. The iron oxide covering is what gives the apparent color change of the nephrite. In another view of the zoomorphic beast in figure 22, greyish white phyllosilicate clay crystals are on top of the iron oxide crystals (Figure 23c). Notice also the straight silvery metal line indicated by the red arrow. The appearance of
the buried nephrite is the result of the secondary products from Chemical Weathering accumulating on the jade surface. The iron oxide encasing with phyllosilicate crystal formation on top is also illustrated by the Neolithic disc on the front cover of Jessica Rawson’s book. “Chinese Jade, From the Neolithic to the Qing.”
Silvery metallic granules are often in a line. Those on the Hongshan zoomorphic on top of a worm (Figure 24) are in a group. Figure 25 is the magnified view of the jade surface with a group of metallic granules marked in a red circle. Around these
granules are the sheet-like phyllosilicate crystals of the clay minerals. Viewing buried nephrite with naked eyes can be deceptive. The surface on the C-dragon – pig dragon in figure 26 appears damaged on observation. Such an effect is often simulated by fake jade makers with sandblasting, and color manipulation by driving in dye and paint with heat
and Ph, to obtain such appearance. Under the microscope, it becomes evident that such appearance is not damaged but is due to the accumulation of secondary weathering products on the surface, entirely different from that on the fake jades. In other words, weathering changes on the buried nephrites cannot be simulated, and recognizing such changes is a good tool for authentication.
As a group, Hongshan jades are buried the longest, for 5,000 to 6,000 years. The long burial time results in a large amount of secondary product accumulation on the surface, and hence with the most pronounce chemical weathering effects. Two clay minerals are formed, Smectite and Kaolinite. Clay minerals are phyllosilicates that form sheet-like crystals, and the accumulation of the crystals is what gives the irregular appearance of the surface. Figure 27 is the magnification of the C-dragon – pig dragon surface. Notice the thicking of the greyish-white crystals is what gives the appearance of
an irregular surface. Crystals have structure as noted on the right side of the magnified field, as opposed to the fake jades with white powder forming a thick paste. As the phyllosilicates come from a ferruginous gel, the presence of iron oxides gives the color a brownish tint. Variation of crystal form exits in different parts of the same jade piece due to many sub members of the clay minerals form various shapes of crystal. Smectite has 22 members, and Kaolinite has several. Figure 28 is the magnification of a different part of the C-dragon – pig dragon. Notice the difference of the crystal formation, more elongated and string-like than in figure 27. Chemical weathering is a very complicated
process, and much of it is still unknown. Various chemical reactions and numerous mineral formations result in different locations of the same piece of jade with different effects seen under a microscope. Simulation on fake jades is uniform throughout. Understanding this will significantly help in forgery identification.
Very few minerals give out an odor, and clay mineral is one of them, giving out the smell associated with soil. Chinese antique jades’ collectors have long known that buried nephritis has a scent that they referred to as tomb smell. This scent comes from the clay minerals formed from the chemical weathering process. Accumulation of clay mineral from the chemical weathering process on the jade surface increases with time, and only when enough clay minerals form on the jade surface that the buried nephrites can give out such odor. As a result, such odor comes only from jades Han or older, and the older the jade, the stronger the smell.
Crystals on the jade surface formed from the chemical weathering can have different shapes and forms. Figure 28a, also a magnification of the C-dragon – pig dragon, shows a patch of tile shape crystal within the two red circles. Such often found in
isolated patches crystals likely is pseudomorph formation. Pseudomorphs are minerals with chemical substances of one kind and a mineral crystal form of another kind as it alternates from one mineral to another. Pseudomorphs, often referred to as Raised Relief on Chinese nephrites, form in the geochemical world, when conditions become suitable. An example of natural pseudomorph is in figure 29, a Limonite pseudomorph after Siderite. Nephrites, when buried, return to the geochemical world, and pseudomorphs
form. As pseudomorphs take time to develop, they only occur on nephrites Han or older. When they occur, they are multiple. Figure 30 shows a late Zhou to Qin (201-206 AD). Jade man with numerous nodules on the body. Under microscopic magnification, these
nodules are formed by tile like crystals (Figure 31). Raised relief or pseudomorphs are
more often found in Hongshan jades for the apparent reason of the Hongshan jades’ longest burial time. Figure 32 is a Hongshan zoomorphic beast with multiple raised relief
on its body. Under the microscope reveals the similarity of the tile like crystal structure of these nodules to those in figure 31 (Figure 33). One difference between the two is that
there are metallic granules found on the nodules on the zoomorphic beast (Figure 33a), whereas metallic granules are not found on the jade man. Such a difference may indicate
that the chemical composition of the nodules is different between the zoomorphic beast and the jade man and that iron oxide are present in the secondary products in the zoomorphic beast giving the zoomorphic beast a reddish color. Pseudomorphs alter from the original mineral to a new mineral depending on the environmental influence. Raised relief on one jade surface may be a different mineral from raised relief on another jade surface. Figure 34 is a natural Agate pseudomorph. Notice the similarity of the crystal
arrangement between the Agate pseudomorph and those on the jade man (figure 30 and 31), and on the Hongshan zoomorphic (Figure 32 and 33). Figure 35 is another Hongshan
zoomorphic beast. The pseudomorph on this zoomorphic beast (Figure 36) is completely
different from those on the jade man and the zoomorphic beast in figure 32 and more like the Limonite pseudomorph in figure 29. The different types of pseudomorph are further demonstrated in figure 37, another Hongshan zoomorphic. The pseudomorphs
on its body all have a Smoke Quartz appearance (Figure 38). All of these say that the
raised relief on the buried nephrite may have different chemical compositions. There is one essential consideration when comparing pseudomorphs on the jade surface to the naturally occurring ones. The naturally occurring pseudomorphs are in general ten thousand years or older, whereas the pseudomorphs on the jade surface are at the most 6 thousand years old.
The chemical weathering process continues to take place within the surface micropores and microcracks of the jade surface, producing a ferruginous gel-like substance that eventually spills onto the jade surface, forming a thin semi-transparent crust. Such crust is hard to discern under the microscope unless the semitransparent crust is cracked, as on this Liangzhu (3400-2250 BC) disc with three birds (Figure 39).The
crack becomes apparent when the disc is examined under the microscope ( Figure 40). A
small piece of the crust is lost, exposing the undersurface of the disc seen in the area within the red circle and on further magnification (Figure 41). The defect on the crust
can now be seen, providing proof that such a crust exists. The ferruginous substance can thicken into a plaque on the jade surface. Figure 42 is another magnification view of figure 26, the C – dragon pig dragon. Amid greyish-yellow phyllosilicate crystals is a clear
plaque with an edge adjoining the clay phyllosilicate. At the center of the plaque, are silvery metal granules forming a straight line, identified within two red arrows. The presence of these metallic granules affirms the plaque is ferruginous. The color and the semi-transparency of the plaque are frequently mistaken as the jade surface looking at it with naked eyes and widely simulated by fake jade makers by covering part of the fake jade with dye and other parts without. Seeing such a pattern of an exposed jade surface can be a clue of forgeries.
The presence of the weathering crust on the jade surface is a good indication that the jade piece is genuine. This thin crust is only about 0.1 to 0.2 mm in thickness, comprising of clay phyllosilicate and iron oxide minerals. Many geochemical changes can be observed on this thin crust. Figure 43 is a Hongshan pig dragon beast. On it is a
group of brownish granules within the semitransparent crust (Figure 44). Such granules
black or deep brown in color and often referred to as charcoal, are Hematite inclusions formed inside the ferruginous gel. Hematite can also be reddish-brown. When it forms as a crust, it creates an optical illusion that the jade piece is reddish-brown in color, as we have already seen on the zoomorphic beast in figure 23. Figure 45 is a Han beast disc. A
magnified oblique view reveal the coloring is due to surface Hematite encrusting (Figure 46). Iron oxide encrusting is a frequent finding in Hongshan jades, as on this Hongshan
zoomorphic insect beast (Figure 47). Again, to appreciate the presence of the crust, an
oblique view under the microscope is essential (Figure 48). The different colors on the
jade surface is due to the different mineral formed. The red and black are from iron oxides, and the greyish white is from the clay minerals. Figure 49 is another view of figure 47, the zoomorphic insect beast. The crust essentially becomes the jade surface
taking on the color of the secondary products as well as defects like the cracks that are in the crust rather than in the jade (Figure 49). Weathering product iron oxide in the crust can result in various colors of the Hongshan jade. The color change on the Hongshan eagle in figure 50, is likely from Goethite, as also likely the Hongshan bird zoomorphic in
figure 51 that has a distinct crystal formation (Figure 52a). Figure 52b is an oblique view
of the jade surface. The iron oxide crystals are clearly on the surface of the jade piece. The beautiful color on the Neolithic disc on the cover of Jessica Rawson’s book, “Chinese Jade, from the Neolithic to the Qing” is not a natural color. The color is from the iron oxide formed on the jade surface similar to on the zoomorphic bird in figure 52.
There is a mineral formation unique to Hongshan jade. Figure 53 is a
Hongshan bird with a worm on its head. The unique mineral finding is inside the drill hole as in figure 54. The pin-like crystal is an iron oxide, most likely Goethite. Drill holes
preserve water and have a cave-like environment suitable for mineral development. This phenomenon is rarely seen as such mineral formation is uncommon. Although fragments of this type of mineral can be found inside other drill holes, a fully developed formation can only be found in one other Hongshan Jade, a zoomorphic with a beard (Figure 55). Inside its two obliquely drilled holes on its back are multiple of such mineral formations( Figure 56).
The key to distinguishing a genuine buried nephrite from forgeries is to recognize the color change on the jade surface comes from the secondary weathering products, clay minerals, and iron oxides. Only when the secondary product crystals are seen on the surface, authenticity can be ensured.
Through Jade to Hongshan cultural beliefs
Throughout Chinese history, jade has been regarded as a stone with mysterious power, a belief especially true during the Neolithic period, and hence jade was exclusively the medium for expressing religious beliefs. As with any art form, such expression reflects the thinking of the carver. Through jade, the carver presents his thought and outlook of his world and his perception of beauty to the viewers. With the Hongshan culture leaving no written record, jade provides a path for a glimpse of the thinking and the religious beliefs of the culture. Artistically, Hongshan jade, even with all the limits of being a Neolithic culture, attains a high artistic level, not less than any subsequent Chinese culture periods, thousands of years after.
The majority of the Hongshan jades are small, measured 3 to 8 centimeters. Most of the small piece has hanging holes like those discussed in the drill mark section above, indicating that such small pieces are for hanging on the body. None of the large pieces, which can measure up to eighteen centimeters, has hanging holes, except the hook cloud plaque (Figure 57), that can measure to 23 centimeters. With drilled holes on
top and to the sides, the Hook Cloud plaque most likely was for hanging on the human body. Some speculation that the plaque is an abstraction for a religious belief. Other large pieces longer than 15 centimeters like the zoomorphic beast in figure 35, and the zoomorphic insect beast in figure 47, as a rule, do not have drill holes as they probably are statues rather than a hanging piece.
Most of the Hongshan jades are beasts with human characteristics, a form of zoomorphic. These beasts zoomorphic intermingle with birds and insects often on top of the head of the beast. The pig dragons and C-dragons are a class of its own. Chinese scholars believe they are the forerunners of the Chinese dragon. Their faces, however, resemble that of a Hongshan beast (Figures 58 and figures 9a and b). The pig dragon is
more versatile and often combines with another subject, as with the C-dragon in figure 26. More often, the pig dragon combines with the zoomorphic beast (Figure 43), and in figure 58, in semi human form with a pair of human legs. A more complex pig dragon is in figure 59, one with a zoomorphic beast head, losing the characteristic pig dragon eyes connected with a pair of lines, and a pair of insect or bird wings. Both pig dragons in figure 58 and 59 give an impression that the pig dragon can evolve into other forms. In
another word, it is a therianthrope rather than a zoomorphic. It is quite often that the Hongshan animal and beast, as the pig dragon in figure 59, take more than one form. In figure 47, the zoomorphic beast is also part insect, and in figure 55, the zoomorphic beast is part bird and part insect. The combination forms may mean the Hongshan beast, man, insect, and bird can evolve into each other and are more likely therianthropes.
The Hongshan beasts and animals are not necessary a zoomorphic with more than one entity in one form but can occur as two different individuals. Figure 60 is a pig
dragon on top of a beast, and figure 61 is a beast on top of a pig dragon. Notice both the
pig dragon and the beast in figure 60 are facing the same direction, and the beast and the pig dragon in figure 61 are facing the opposite direction. Direction pointing is often a theme in the Hongshan culture, as we have seen on the ox nose part of the through and through drill holes on the C-dragon (Figures 8 and 9). Figure 62 is a beast. On its back is
an owl facing opposite to the beast, resulting in both the beast and the owl showing the front (Figure 63). The beast zoomorphic in figure 64 also has an owl on its back. But in
this case, it is the owl’s back we are seeing as the beast and owl are facing the same direction (Figure 65). Figure 66a and b is a bird standing facing forward on top of a zoomorphic beast. This statue was a pair. Unfortunately, figure 66 is the only one in my
collection. The other statue, the bird on top of the zoomorphic beast, faces backward. The theme of direction pointing, at a time in the same direction, and in others in a direct opposite is consistent in Hongshan jades. These Hongshan jade carvings illustrate clearly the concept of the same and opposite in the form of direction, as we shall see later also in the form of the two different sexes.
The goddess temple and the six pregnant female clay figurines excavated from the Hongshan archeologic site lead to the belief that Hongshan is a fertility worship culture. Hongshan is also the only Chinese culture period that displays the female figure in their jade art by carving breasts on the female characters, as on the female bird
zoomorphic (Figure 67), and the two female beasts zoomorphic (Figures 68 and 69). All female characters have round eyes and all female beasts zoomorphic sit in a semi kneeling position on their legs. This sitting position is like that of the later Shang and Zhou period, tracing back a long tradition. The male counterpart has almond-shaped eyes, and most of the male beast squats (Figure 70), with less often sits on the ground (Figure 71). Both the male and female may stand. Notice also are the two different types
of horns on the female zoomorphic in figure 68 and the male zoomorphic in figure 70. It is possible that these are not horns of the beasts, but headgears or even hairstyle of the Hongshan period. The shape of the eyes differs between males and females with female eyes round, and the male eyes almond-shaped, provides clear identification of gender in human, beast, bird, or insect. Most birds have round eyes. The almond-shaped eyes on the bird in figure 72 distinct him as a male, a contrast to the round eye bird in figure 53,
the female bird zoomorphic in figure 67, and the female beast in figure 68. Males and females are often in pairs, and when they are in pair, each faces a different direction. Figure 73 is a pair of males and female zoomorphic beasts with each facing an opposite
direction. The two zoomorphic beasts of opposite sexes in figure 74 facing up and down. Figure 75 is a pair of bird beast zoomorphic, back to back in two directions with the smaller round eye female on the back of the bigger almond eye male. The opposite position emphasizes the contrast of male and female consistent with the opposite directions indicated by the ox nose on the C-dragons, and the opposite directions facing by the zoomorphic, birds and beasts. What it shows is the idea of opposing directions of front and back, forward and backward, up and down, female and male, are in one, a philosophy that may well be the embryonic beginning of Yin and Yang.
Pregnancy is a theme in the Hongshan religious belief. From the excavation of the Hongshan archeology site, there are six pregnant female figurines. Such theme of pregnancy also reflects in the jade carving. Figure 76 is a pregnant beast zoomorphic.
Unfortunately, none of the figurines retains the head. Having human-like breasts in these figurines may not mean they are human, as seen in figure 67, the female bird zoomorphic also have human-like breasts and a bird head. The zoomorphic in figure 76 has a protruding abdomen indicating pregnancy. The head of the beast has a C-dragon crown and a pair of two lines connected eyes. A connection of eyes in such a manner is only in the pig dragon. The combination brings in the importance of the C-dragon and the pig dragon in relation to life. Such a combination also confirms that the beast is a therianthrope as it shows more of a change from the human, beast, to C-dragon and pig dragon as opposite to a zoomorphic, a human in beast form.
A unique bottomless tube (Figure 1) thought to be religion related is also a subject of the jade carvings. Figure 77a and b is a turtle climbing up such a bottomless tube, and figure
78 shows a bottomless tube on the feet of a bird zoomorphic. The association of the bottomless tube, the turtle, and the bird zoomorphic may indicate the Hongshan
religious belief is related to nature, an interrelationship between humans and birds, insects, and beast. Both the bottomless tube and the jades are found only in graves, making such a relationship likely an afterlife belief.
Often found in Hongshan carved nephrites are insects, birds, and beasts on top of a larger beast zoomorphic. Figure 79 a and b is a beast zoomorphic with two
winged insects on its head. The eyes of the insects become the beast zoomorphic eyes. Figure 80 a and b is a small beast on top of a larger beast zoomorphic. Figure 81 a and b
is a bird on a beast zoomorphic, and figure 82 a and b is a double-headed beast on a larger beast zoomorphic. These carvings further demonstrate the close interrelationship
between human, beast, bird, and insect in the Hongshan belief. All the zoomorphic with an insect, bird, or a small beast on their head have almond shaped eyes indicating they are male beasts. The eyes of the beast zoomorphic in figure 79 are the eyes of the insects. But the squatting position tells that the beast is a male. There are also carvings with a human face. Figure 83 a and b is a man’s face and figure 84 a and b is a man’s face with two legs attached to it. Both have a winged insect on top of their heads. The similarity in
position, as well as the similarity of the insects on their heads, may indicate the male beast zoomorphic and man are interchangeable and identical. The meaning of the insect, bird, and beast on the heads of man and beast cannot be known. But that it only associates with males indicates male is a special class. Only other human face on the carvings is this female beast zoomorphic with a human face mask behind her head (figure 85 a, and b). No insect, bird, or beast appears on the head of the female zoomorphic, a distinct difference from the male counterpart.
Hongshan was a Neolithic culture 6,000 years ago. To many people today, the culture was primitive. Such an assumption is reflected in people who carve forgeries, creating jade pieces they believe primitive and call them Hongshan jade. Without the opportunity to see an authentic Hongshan jade artifact, the fake jade carvers produce inferior objects out of their imagination of what they believe a Neolithic primitive culture artifact. Such imagery permeates Chinese society today. Yet the Neolithic people of Hongshan carved out jade pieces that are both technically and artistically advance even in today’s standard. The technique they used was principally grinding with abrasive, leaving behind a smooth jade surface with minimal tool marks. The most frequently found tool marks are inside drill holes. Drill holes are made with bone drills and abrasives, leaving behind shallow, irregular and circular marks on the side of the drill hole (see figure 13). Most of the Hongshan jades are round three dimensional. Without the benefit of today’s instruments, the Hongshan carvers were able to carve zoomorphic beasts squatting on their two feet, essentially putting the center of gravity of the mass onto two small points ( figures 32, 37,80 and 84), something that today’s fake jade carvers cannot achieve. Most of the jades are superb artistically. Consider the beautiful geometric curve of the C-dragon (figure 9), the line management of the female beast (figure 22), the imaginative birdman (figure 51), and the balance in the abstraction of the hook cloud plaque (figure57). One can go on and on. If one cannot see artistic beauty in a Hongshan jade piece, one can very much doubt the authenticity of it.
Using abrasive has always been the foundation of jade carving in China. From the Neolithic time to the Zhou Dynasty, the technique was grinding with the use of abrasive, a tedious and time-consuming process, but left behind a smooth jade surface with little to no tool mark. During the Han Dynasty, latches came into use also working with abrasive. Jade carving became more efficient, required far less time to accomplish, but also left behind distinctive tool marks. Such a technique very much continues to the Qing Dynasty (1644 – 1912) resulting in tool mark similarity between the jade made before Han and after Han.
Jade of each period and dynasty has different style and characteristic. Hongshan jades are of no exception. Hongshan carvers often combine two characters into one piece, a form that has not seen in any period of Chinese jade. Such a combination often presented creatively. Figures 86 a, b, and c show a beast combining with a cicada. The front is the beast, the back the cicada and with the bottom the cicada
face. Hongshan carvers also have a sense of humor. Figure 87 a, b, and c is a piece that looking at it from one side is a face (figure 87a). Turn the piece around, and there is another face (figure 87 b). The back side is a frog on a leaf (figure 87 c). The Hongshan
jade is genuinely an art form in no sense inferior to any other period. Notice the crack line on figure 87a. The crack line is curved an indication the crack is on the secondary weathering chemical. If it is on the jade itself, it will be straight due to the structure of the nephrite crystals. Also, notice the similarity between the human face in figure 87a and the cicada face in figure 86c, consistent with the Hongshan theme of interchangeability and intermigration between humans and animals.
From Hongshan to Han
One of the mysteries in Chinese antiquity is the meaning of a beast face that appeared on the Shang (1600 BCE – 1046 BCE) and Zhou (1046 BCE – 256 BCE) bronze ceremonial wares (Figure 88). The beast face also appears on a Shang jade vase (Figure 89 a and b). The origin or the meaning of such a beast face has led to many speculations
with no answer for certain. Tracing back, the only resemblance of the Shang beast face is the face of the Hongshan zoomorphic beast. The question is that can the Shang beast face has an origin in the Hongshan beast zoomorphic. Figure 90 is the face of the Hongshan zoomorphic beast with a bird on his head (Figure 66a and b) and look again at figure 86a
the beast face in front of the cicada. Figure 91 is the Hongshan zoomorphic beast in front of the hook cloud plaque in figure 14. The hook cloud plaque is an abstraction that has a
ligious meaning. The presence of it behind the zoomorphic beast gives the zoomorphic beast a religious significance. When comparing the three Hongshan beast faces, figures 86a, 90 and 91, to the Shang bronze and jade vase beast faces in figures 88 and 89, the similarity between all these faces is there, making it very likely that the Shang beast face has an origin in the Hongshan zoomorphic beast.
But if that is the case, why did the people of Shang carve the Hongshan zoomorphic beast face onto their ceremonial bronze wares. The answer lies in two Liangzhu culture (3400 BCE – 2250 BCE) jade butterfly plaques (figure 92 and figure 93).
Liangzhu is another Neolithic jade culture in China, overlapping in time with Hongshan (4700 – 2900 BC), coexisting at the same time for five hundred years. Physically they were a thousand miles apart. The Liangzhu culture has three images carved on their jades, the godman 神人 (figure 94), and the two god beasts 神獸 seen in figure 92. The godman is the ancestor king, and the two misnomer god beasts are symbols of human representing the
present living king and the ancestor king. The lower god beast with a nose in figure 92 is the symbol of the ancestor king and therefore is carved on the body of the godman, the ancestor king, in figure 94. The upper god beast without a nose in figure 92 is the symbol of the present living king, and therefore is carved on the cones, axes and beads, personal belongings of the current living king. (The explanations of the godman and god beasts are found in the blog post “良渚神人神獸的意義及其宗教中心思想,” in this web site). Except for the one on the lower part of the butterfly plaque in figure 93. the Liangzhu culture has never carved the beast face on their jades. This beast face is the first-ever beast face in Chinese history, predating the Shang (1600 BCE – 1046 BCE) by at least one thousand years. As the beast face is not part of the Liangzhu culture, there must be a base for this beast face carving, and the only possible source is the Hongshan zoomorphic beast. In figure 92, the Liangzhu god beast with a nose occupies the lower position of the butterfly plaque. In figure 93, that position is replaced by the beast face. Since the Liangzhu god beast with a nose is the symbol of the ancestor king, the replacement of it with the beast face indicates the beast face carries the same meaning, that It is also a symbol of the ancestor king. The Shang ceremony is to worship and honor the ancestor kings. It is, therefore, logical to have the beast face, a symbol of the ancestor king carved on the ceremonial bronzes.
Since the Neolithic time, in the subsequent periods in Chinese art, the beast face is not as frequently seen on the jades as on the bronze. It appears on a Zhou Dynasty disc as abstract designs (figure 95). It also appears on a seal (figures 96a and b). This seal
has a beast knob, and on the four sides, four beast faces. Four characters are on the seal surface 黃漢起印. The name indicates that it is the seal of a general 黃蓋in Han of the Three Kingdoms period (220 -280 AD). After Han, the beast face is no longer seen in China. The disappearance has to do with the tremendous change in Chinese culture after Han. Both the bird and the beast face represent the ancestor king, with the beast face as the symbol, and the bird believed to be the medium of the ancestor king’s soul when he makes his journey to the sun (explanation in “渚神人神獸的義及其宗教中心思想”). Such religious belief is the reason why both the beast face and the bird are on the ceremonial bronze and the Shang jade vase (figure 89a). After the Han Dynasty, Buddhism came to China. Buddhism replaced the original religious belief of ancestor king worship and with it the ancestor king symbol of the beast face and the bird. Yet ancestor worship remains in Chinese society even today. The Hongshan and Liangzhu spirit are still deep in Chinese culture.
Hongshan religious beliefs
The Hongshan jades present a pattern through which it opens a path to the thinking and beliefs of the carvers. The finding of the goddess’s head and the pregnant female figurines at the temple site show Hongshan was a fertility worship culture. This belief is also reflected in jade in the pregnant therianthrope (figure 76). The bottomless clay tube thought to be of religious significance is also found in the jade carving (figures 77 and 78). Jades are buried in graves and should express the religious belief of the afterlife apart from the fertility worship associated with the temple. Often the jade carvings are zoomorphic beasts, semi-human, with birds and insects. Some combine more than one as if it is in transformation, a therianthrope rather than a zoomorphic (Figure 59). Such a transformation afterlife may indicate the Hongshan belief in reincarnation or transmigration after death. Reincarnation or transmigration is a universal human belief shared by people in India, ancient Greek and, Rome, natives in North America and Australia. That this is may also a belief in the Hongshan culture should not be a surprise.
The Hongshan zoomorphic beast, birds and insects, all show a clear distinction between males and females, with males have almond-shaped eyes and females have round eyes. Male and female are often set in one piece facing the opposite direction (figures 73, 74, and 75). The concept of opposing directions and yet form as one is also shown by the ox nose part of the round drill holes on the C-dragons and the opposing direction facing by the zoomorphic beasts and birds on the same jade piece ( figures 63, 64 and 65). This thinking, together with the male and female opposing but complement each other into one piece, is very much in line with the Yin and Yang philosophy that comes later into the Chinese culture.
Hongshan jade also gives us a glimpse into a Neolithic society, a society with men and women playing different roles, the males into the position of kings, and females into the role of fertility. The beast zoomorphic in the Hongshan culture and the godman, god beasts in the Liangzhu culture, all represent ancestor kings’ worship that passed on to the Shang Dynasty and influences the Chinese culture even today.
2004年大英博物館發表了一篇論文,(The identification of carving techniques on Chinese jade, Margaret Sax, Nigel D. Meek, Carol Michaelson, Andrew P. Middleton; Journal of Archaeological Science 31 (2004) 1413-1428). 作者把六件大英博物館所藏中國玉器玉面上的工具留痕打模, 然後用電子顯微鏡檢看所得模型, 以鑒定留痕是從那種工具所留下. 六件玉器中有一件紅山玉鳥. 但在玉鳥上, 並没有找到留痕, 唯一 找到的是在掛洞中的頂上兩洞相接處, 留有拉線切割的痕跡. 紅山玉器被埋在地下有五六千年, 可說是世上埋在地下最久被雕刻過的軟玉, 因而化學風化的程度最深, 而風化可把工具痕跡遮蓋. 且紅山玉器主要是磨製, 平滑的玉面經打磨後, 留下極少的工具痕跡, 鳥獸人物的刻劃, 主要是用淺而寬的坑. 線條也是淺而寬(圖3), 眼鼻都是宊出
Ten years ago, as a tourist in a remote Central America tourist destination (not Mexico), I saw a street peddler, selling stone made tourist items. Behind all his poorly made uninteresting items was a single green stone statue that stood out as unique. With no knowledge of the South American culture, the first thing that came to my mind was Chinese fake jades coming to Central America. Curiosity drove me to picked up the statue and looked at it carefully. The statue was a handmade jadeite. Part of it was done by chipping and flicking, a technique not used by Chinese jade carvers ancient or recent. This could not be Chinese made. As it fitted into my category of souvenir with a local flavor I decided to buy it. After a short hackle, the man agreed to sell the statue for 75 US dollars. Later research showed that a similar statue was in the Dumbarton Oaks collection, the Aztec goddess Tlazolteotl carved between the late 15th and early 16th century. Tlazolteotl was a goddess of filth and vice, especially sins of sexual misdeeds. Paradoxically she also was the patroness for forgiving sins of such misdeeds, and a purifier for sins and diseases caused by these sexual transgressions. These seemingly contradicting believes made her the goddess of purification, steam bath, midwives, filth and adulterers and appropriately as a statue of a woman giving birth. At the time these were interesting but not for long. It was promptly forgotten and ignored for ten years, sitting among my other memorabilia from my travels. Recently when I was researching for Chemical weathering on buried nephrite jades, I came across the article, “The Dumbarton Oaks Tlazolteotl: looking beneath the surface “, by Jane MACLAREN WALSH, JOURNAL DE LA SOCIÉTÉ DES AMERICANISTATE, 2008, 94-1. “ (To read the article and to see a picture of the Dumbarton Oaks Tlazolteotl , click on the following link). http://journals.openedition.org/jsa/8623 The Dumbarton Oaks Tlazolteotl was found to be made in the 19th century. The jadeite Tlazoteotl in my collection was taken out and looked at carefully under a 40X stereomicroscope. It is my belief that the existence of a jadeite Tlazolteotl and the finding on the statue deserve to be known. All of the descriptions and history of the Dumbarton Oaks Tlazolteotl are based on the detail study by Jane Maclaren Walsh in her article.
Comparison of the Dumbarton Oaks Tlazolteotl and the jadeite Tlazolteotl.
Fig.6b Left profile
Fig 2.Right profile
Fig 2. Back.
The jadeite Tlazoteotl seen above, measures 14 cm in height, 8cm in width from side of knee to side of knee, and 8 cm front to back also taken from the level of her knees. This makes the jadeite a smaller statue than the 20 cm tall Dumbarton Oaks. It is made of a pale solid green jadeite. Unlike the Dumbarton Oaks Tlazoteotl which is in a sitting position, the jadeite Tlazoteotl is in a squatting position with her buttock above ground squatting squarely on her feet. Also unlike the Dumbarton Oaks Tlazoteotl who has her neck extended, head tiled backward with a grimace expression, the jadeite Tlazoteotl faces forward with an expression of regret and sorrow, as if she is going to cry, a face of a woman in depression. (See below fig. 3). Both her eyes and nostrils are irregular comparing to the Dumbarton Oaks Tlazoteotl. She has higher cheek bones, thicker lips
and prominent eyebrows. There is no drill hole on her. Her mouth gaps open with well defined teeth on her upper jaw and no teeth on the lower jaw, a difference from the Dumbarton Oaks Tlazoteotl that has well defined teeth on both the upper and lower jaw. It is interesting that many of the Pre-Columbian jade masks in museums only have teeth on the upper jaw. The lower jaw either has no teeth, or represents by a smooth ridge, similar to the jadeite Tlazoteolt. Fig 4 below shows the mouth of the jadeite Tlazoteotl on the left as compare to an Olmec mask from the Latin American studies, http://www.latinamericanstudies.org/olmec-masks.htm on the right. Similar finding can be seen on the Olmec mask in the Metropolitan Museum of Art https://www.metmuseum.org/art/collection/search/310279 , and in the Boston Museum of Fine Art http://www.mfa.org/collections/object/portrait-mask-36451.
Fig. 4a. Mouth of jadeite Tlazolteotl with well defined teeth on the upper jaw. Only a smooth ridge on the lower jaw.
Fig. 4b Olmec mask
On the body of the jadeite Tlazoteotl, like the Dumbarton Oaks Tlazoteotl, she has well defined clavicles. Unlike the Dumbarton Oaks Tlazoteotl that has well carved breasts with well inscribed nipples, the breasts on the jadeite Tlazoteotl are represented by two triangular masses with no nipples. Her knees are separated at 3 and 9 o’clock. Both hands are carved, holding her buttock. More differences are found between the infants of both statues. The Dumbarton Oaks Tlazoteotl infant has a full headed of hair and well defined facial features resembling very much of an adult. The jadeite Tlazoteotl infant has no hair and less elaborate facial features. (Fig. 5) Unlike his mother, his eyes are
round, Both statues lower legs are angled backward, a very significant finding as to the positions they are in. The similarities between the statues give the impression that there is a relationship between the two statues. But the discrepancies are significant making it unlikely that they are copies of each others.
The birthing positions of Tlazoteotl
The birthing positions of both statues in are unfamiliar to modern eyes. To understand the feasibility of the positions, I tried both positions myself. The jadeite squatting position (Fig. 6 ) was attempted first. Squatting down, the more I spread my legs the
Fig.1. Jadeite Tlazoteotl
Fig.6b Left profile
more I could keep my upper body upright. My lower legs angled automatically backward. If I squatted down too low, I tended to fall. By placing both of my hands underneath my buttock, I could actually lift my body slightly upward, and kept my balance. The jadeite squatting position is not only feasible, and placing both hands uner the buttock is a good way to stabilize oneself in that position.
Next I attempted the Dumbarton Oaks Tlazoteotl sitting position. ( See Fig. 3 in the Dumbarton Oaks Tlazoteotl article http://journals.openedition.org/jsa/8623 ). With myself sitting on the floor legs bent in front of me, I was unable to keep my upper body upright. The position forced me to lean backward. To support myself, I had to place both of my hands out on my sides and back. Placing my hands underneath my buttock was impossible. With my legs spread apart my lower legs bent angled forward. An attempt to bend my knees to angle my lower legs backward resulted in severe strain on both knees causing great pain. The biggest problem is the infant. In this position, as the infant emerges, his head will hit the ground, and the length of the baby will prevent him from coming out safely, unless the woman leans way back to almost flat on her back. My conclusion is that the Dumbarton Oaks Tlazoteotl sitting position is not only impossible to obtain, but is also unsafe to give birth.
There are many versions of position to give birth today. The most common one is the woman lying on her back with her legs up spread wide apart, knees bent angling backward in stirrup. This is a lying version of the squatting position. If you rotate the picture to put the woman’s body upright and feet down, you can see her actually is in a squatting position. The squatting position the jadeite Tlazoteotl in is a natural position to give safe birth. A woman can be in a sitting position when she is in labour. As soon as the infant is crowning, she has to go into the squatting position for delivery, especially if she is by herself. Going into the wood by herself to give birth is a known American Indian women practice. The jadeite Tlazoteotl lacks the authoritarian, self confidence and commending expression of nobility and goddess. Her expression shows psychological pain more so than physical, of a woman in depression, a phenomenon common during pregnancy before or after the delivery. Such psychological trauma cannot be experienced by a man. The jadeite Tlazoteotl is more likely carved by a woman.
Tool marks on the jadeite Tlazoteotl
The tool marks on the Dumbarton Oaks Tlazoteotl were thoroughly studied using Scanning Electron Microscopy on positive silicon impression technique. It iwas the tool mark study that confirmed the Dumbarton Oaks Tlazoteotl was carved in the 19th centaury. No sophisticated examination can be done on the jadeite Tlazoteolt . However examination under a 40X stereomicroscope can still yield insights into the statute. In her article, Jane MacLaren Walsh gives a detail account of Pre-Columbian lapidary technology. The tools used were essentially hard stones and various types of sand abrasives. The stone to be carved was first cut to size splitting with wood wedges,or cutting with lines or stone saws. Techniques used for more detail carving were chipping, scrapping, grinding, filing, and piercing with solid pointed stones, all with stone tools and abrasives. Drilling were done with bamboo or bone. The surface was then polished with materials like wood and animal skins together with fine abrasives. With that in mind, lets look at the tool marks to see how the jadeite Tlazoteotl was carved.
The first time when I picked up and looked at the jadeite Tlazoteotl, the feature that caught my eyes was these undulations that look like nodes on short intervals, on the surface of the arms. (Fig. 7 on the left picture below) These result from chipping, or sometimes called flinting. An example of Neolithic knives on the right picture below shows such effect. The Neolithic carver used a sharp and hard stone tool like flint to
Rise and fall with nodes like intervals on the arm.
Neolithic knives from chipping.
carve the knives. He stroked down at an angle towards the stone to be carved. As his tool hit the stone, he flicked his wrist to direct his tool upward, to avoid cutting too deep into the stone. This resulted in a shallow pit with raised edges, as seen on the stone knives. The jadeite Tlazoteotl carver then further scraped and grinded to rid of the roughness, and finally polished it into the arm. Ridges are left, giving the arm an unique look of the chipping.
The eyes of the jadeite Tlazoteotl also tell the story of how she was carved (Fig. 8). Both eyes are almond shape, an indication that they are not drilled. The wall of the sockets
Fig. 8 Right eye
Fig. 8 Left eye.
are carved straight down. The bottom of both eyes are uneven slopping up from the side to the center resulting in a small mound. The carver used a chisel like stone tool pecking straight down on the side of the eye socket making a groove. He then went inside the eye , and with his tool slanting towards the groove on the side, he chiseled away the stone material to make the eye. By repeating the chiseling, the stone material inside the eye eventually was all chiseled away leaving the eye formed as a void. The result is an eye with a straight down socket wall, and a bottom sloping up from the side towards the center, as with the jadeite Tlazoteotl eyes. The eye then became a small pit, too deep for stone tools to scrape and grind and polish like he did with the arms, leaving the roughness and a small mound at the bottom.
The lines on the jadeite Tlazoteotl are crude and thick, most notably on lines that represents her hair (Fig. 9). The space between the lines are wide and uneven. The width
of the lines are inconsistent, with bulges at various part of the lines. The lines are filled with soil that I have not removed. Through the exposed part and through the effect of the chemical weathering, thin scratch lines can be seen along the bottom, indicating that these lines are formed by scraping and or filing. All lines have a depth of about 2 mm. There are frequent breakthrough and intrusion outside of the lines, more notably on her ears (Fig. 10). On her left ear, as the carver tried to make the line curve, and as he was
limited by his straight stone tools, to make the turn, he repeatedly file the same part of the line back and forth at a different angle, resulting in bulging of the line at the turn, and notches made by the tool going through outside the opposite side of the line. All the tool marks indicate that the jadeite Tlazoteotl was made with stone tools. The statue is not in good proportion. Her head, thighs and legs are too large for her body, and her arms too short. She has a beauty of naiveté, often seen in Mesoamerican arts.
Chemical Weathering effects on the jadeite Tlazoteotl.
Appication of chemical weathering effects in Archaeology to my wishful thinking is in its infancy. In reality it probaly has not been born yet. Waiting to be recognized is that observing chemical weathering effects on buried lapidary is a great tool for Archaeology, espicially to idetify recently made forgeries. My experience with chemical weathering effect is with Chinese buried nephrite. The statute here is jadeite. Both nephrite, an amphibole, and jadeite, a pyroxene, are mafic minerals, meaning they both are silicates rich in magnesium and feric (iron). According to scientific literatures, chemical weathering process for mafic minerals are similar, only with different secondary products produced, which can vary just by changing the location of the burial site. Changing the locality influences greatly chemical weathering because the climate conditions are changed. Looking at the jadeite statue, the chemical weathering effect may not be exactly like that on nephrite, but they are certainly there on the statute surface.
The first impression the jadeite statue gives is that it has two tones of color, a dark brownish color in the front, and a lighter to close to its original jadeite color on her sides and back. Black patches are on her, mostly on her front and on the infant. These are changes due to the chemical weathering effect. The main ingredient and driving force for chemical weathering is water. The amount of water available to certain part of the statue determines the amount of chemical weathering secondary products produced and that determines the color change. By looking at the color change on the jadeite statue one can tell how she was buried. To see it, the statue is rotated to the position she was buried in with her face down. A darker color on her face, knee and foot (Fig. 11), show roughly a water level. The statue was buried facedown, as if she was in a puddle of
water. More water was availble at the lower part of the soil resulting in more chemical weathering effect on the face and front of the statue. Also noticable are lines as depressed groovs, retained water that produced secondary dark color products, making the lines appear black in color. This secondary product not only delineates the lines, but also form black patches, mostly on the front of the statue. The black color indicates that it probably is related to iron, likely an iron oxide hematite. Looking through Olmac masks on line, the one in the Boston Museum of fine art, has similar black patches on his face.
Chemical weathering secondary products can be formed on the surface. When they form on the surface, a protonation layer where the chemical reaction took place, form. Figure 12 below shows a protonation layer covering the center mound and the wall of the socket on her right eye, as a solid blackish color layer, also seen in the recession above her eye. Secondary products also form inside the surface micropores. As water can
Fig 12. Close up on the right eye showing the protonation layer covering the mound and the socket of the eye.
only penetrate to a very limited depth, secondary products form inside the micropores eventually behaves like a plug, causing further formed secondary products spilling onto the surface. Figure 13 shows the secondary products inside the micropores appear as fine dots with a short length extending down. Because they form underneath the surface,
they appear as if they were under water with a depth. Several kinds of minerals can be form as secondary products. In here most are black, probably an iron oxide, some have a metallic shine, and some have a greenish blue color, most likely a mineral containing copper. A larger patch of the bluish green mineral is found on the inner wall of the right eye socket (Fig.14).
Clay minerals as secondary product can form within the matrix of the jadeite between the jadeite crystals. It gives the jadeite a cloudy look as seen on Fig.13. As more secondary products form, the color change becomes more intense and with time, the color becomes solid giving a patina of the antique jade we all familiar with. Chemical weathering changes occur only within the surface 0.1 mm or so. The optical illusion is what gives the impression that the whole jade piece has changed into that particular color.
The Chinese fake jade makers actively simulate the chemical weathering effect on the jade surface. Such practice does not seem to occur in Latin America. Looking through the on line pictures of the Olmec masks, many of them do not seem to have a chemical weathering effect. They were made with various types of stone with no regard to the stone color of the original. The Chinese also use different types of stone. But always with a color similar to changes from chemical weathering. To create the effect of Chemical weathering, they also use dye, usually with a color dark brown to black, and using heat and manipulating the PH of the solution to drive the dye into the nephrite to simulate the patina color. Such practice also does not seem to occur in Latin America. To identify these forgeries the first thing to realize is that the dye comes down to inside the jade from above. In a natural chemical weathering process the secondary products are produced inside the micropores underneath and spill up to the surface. The dye goes into the jade surface through micro cracks. Under the microscope it shows up as thin lines next to a large patch of dye. In a natural chemical weathering process, the secondary products in the micropores show up as tiny dots frequently away from any large patch of dark chemical, as seen in figure 13. The dye can also infiltrate into the matrix to give a cloudy look color change. Forgeries take a very short time, may be several days, to perform, comparing to the natural weathering process which takes several hundreds and may be thousands of years. Dye altered color change is uneven with areas with no dye showing color of the polished stone. Since the source of the changes come from the dye, large patch of dye on the surface has to be next to these changes. For the buried jade to show a matrix color change requires at least 500 years. The color change is more evenly distributed, and you may not see any dark patches or chemical on the surface. Other techniques to make fake buried jade are using strong acid or alkaline to create a destructive burnt, easily identified under a microscope. Using sand blasting to make holes on the surface is also a frequent forgery trick. Contrary to popular belief, holes on buried jade are not common. It can also be easily identified from natural etch pits under the microscope.
Chemical weathering can produce unusual mineral formation frequently found in drill holes. Reasons for this is drill holes can accumulate a large amount of water, and drilling also creates a large amount of fine granules that remains in a cave like space. Such fine granule when mix with water dissolves rapidly to provide substrate for subsequent chemical reactions. The space also provides a cave like environment for the minerals to develop. The jadeite Tlazoteotl does not have drill holes. But both eyes are carved as voids providing a similar environment. We have already seen a patch of blue green mineral developed in her right eye (Fig.14). In her left eye, on the lower orbit wall, there is a tiny speck of mineral in bright orange color (Fig. 15). The nature of such mineral requires better expert assessment and explanation. Other unusual mineral found are
hair like crystals inside her right eye (Fig. 16). Similar hair like crystals are also found on buried nephrite. The exact nature of these are also unknown. For an amateur there are
Fig. 16. Hair like crystals in right eye.
far too many unanswered questions in chemical weathering. Yet for certain it is a great tool. Its application awaits the scientific community’s exploration.
For many reasons the jadeite Tlazoteotl cannot be authenticated. It has no provenance. Buying it from a street peddler as a tourist is not one. We do know it is not an item made for the tourist trade, since for the last ten years no other jadeite Tlazoteotl was seen, sold to, or bought by a tourist. It is also not an item commissioned by a dealer to sell as an antique artifact for profit. There is no dealer involved, and 75 US dollars cannot even pay for a piece of raw jadeite mineral of similar size. But there has not been a scientific research done on the statute. Looking at pictures on line cannot be counted as one. Top it all, the account is given by an amateur whose experience with Mesoamerican artifacts is limited to one, a number not a statistic. That the statute is Aztec, and may even be its very existence, are at best questionable. However for a meaningful discussion these two assumptions are required.
If the jadeite statue is Aztec, then is the Dumbarton Oaks Tlazoteotl a copy of the jadeite Tlazoteotl? To answer this we must first find out where the Dumbarton Oaks Tlazoteotl was carved. We know that the Dumbarton Oaks Tlazoteotl was carved in the 19th century with power tools. Mexico started electricity in 1879 in Leon. It was privately owned for the textile industry, and electricity was not available to the general public until early 20th century. The Dumbarton Oaks Tlazoteotl therefore could not have been carved in Mexico. Electricity was available to the general public in Paris in 1881, and promptly spread to all segments of the society. Since all power tolls at that time needed to be invented, they had to be the most sophisticated tools available. The Dumbarton Oaks Tlazoteotl could only be carved after 1881 in Paris, by an European artisan with an ability to carve an exact copy of the original. But the discrepancies between the two statues are too great to be an exact copy. So how did the Dumbarton Oaks Tlazoteotl come into being? To answer that we need to go back to the very beginning of the Dumbarton Oaks Tlazoteotl story, described in detail in the Walsh article.
The story is confusing because of so many characters involved. To see clearly, all questionable characters need to be eliminated, leaving those for certain involved. The most important character was Eugène Boban Duverge (1834-1908), a French antiquarian with credentials as the official archeologist in the Mexican royal court, a member of the French Scientific Commission in Mexico, and a dealer of Mesoamerican relics in Paris. The first description of the Dumbarton Oaks Tlazoteotl was in a note hand written by him on May 28, 1883. He also mentioned that the statue was brought in by M. Damour, a mineralogist from the Academy of Science for consultation, and Damour bought the statue from a Mr. Wan who bought it in an auction. The Mr. Wan part of the story was discredited by Walsh in her article. That puts the M. Damour part of the story in question. Hamy, the president of the Paris Amercanist Society, in his 1907 article did mention that the statue was acquired by M. Damour with no mention of where Damour obtained the statue from. In his earlier writing in 1899, Hamy wrote he saw the Statue earlier in Eugène Boban ‘s antique shop, confirming that Eugène Boban was the one selling it. It further put in question that the statue was brought in by Damour to Eugène Boban for consultation. Since Damour was a mineralogist, the reverse may be the truth. Also if Damour did not buy it from Mr. Wan, the only one he could have gotten it from would be Eugène Boban. Eugène Boban was likely the owner of the Dumbarton Oaks Tlazoteotl from the very first beginning.
The most likely scenery of the story is that Eugène Boban commissioned the carving of the Dumbarton Oaks Tlazoteotl, and sold it to Damour in Paris as a genuine Mesoamerican artefact. Eugène Boban had a history of selling known forgeries as genuine artifacts in the Paris antique market, notably the three 19th century made crystal skulls. To carve and made the Dumbarton Oaks Tlazoteotl he must have the knowledge of the existence of such a statue. But all indication he did not see the original. As a well respected and powerful French antiquarian with credential in the Mexican royal court, in 19th century at the height of colonialism in central America, if Eugène Boban saw the original statue, he would have processed it, and if he processed it, he would have sold it in the Paris market like he did with so many genuine Mesoamerican artifacts. The fact that he did not sell an original means he could not have seen it. But if he did not see an original, how could the Dumbarton Oaks Tlazoteotl come into being. Eugène Boban came to Mexico as a teenager. He not only could speak fluent Spanish, he self taught and knew Nahuatl, an Aztec and their descendant language. That means he not only was able to communicate with the Aztec descendants, he also had a very good relationship with them. Also for certain, he was actively inquiring about Mesoamerican artifacts for acquisition. The existence of such a statue was related to him by the Aztec descendants. A picture based on an oral legend was drawn. The picture was the blue print for the Dumbarton Oaks Tlazoteotl, resulting in the similarities and discrepancies of the two statues.
Mysteries are wonderful. The only draw back is there may not be an answer to satisfy everyone.
Chinese culture formation can be traced back to the early Neolithic time (7000BC-5000BC). Nephrite jade appeared early in the Chinese culture as a media, expressing the essence of religion, power and wealth of the Hongshan, Lingzhu and Lingiatan societies. The importance of the nephrite jade continued on to the subsequent dynasties, forming the root of the Chinese culture. Even till today jade still occupies an important position in China. Such importance creates value. Unfortunately value creates problem. Even as early as the Song dynasty (960 – 1279) imitation and counterfeit jade pieces of previous time were found. In today China, with the advance of technology, counterfeit antique jades become rampant to such a degree that real and unreal become blur. On the internet, in many books and videos, identified as reference materials, all you can see are fakes. It is a cultural tragedy when so many people do not know or have a wrong concept of what a Hongshan or Shan, Zhou jade should look like, a loss of cultural identity. The chaos is because there is no true scientific method to identify the true period of jade. Such deficiency and the profit that can come out of it is what creates the tumult. But is it impossible to identify the genuine antique nephrite jade of their period? The answer lies in knowing and understanding the process of chemical weathering. All rocks and minerals undergo the weathering process in nature. Jade when they are buried will be no exception. To try to understand the process, I went through many articles from major research in the world, on the subject of amphibole chemical weathering. Eventually it makes sense to me. Using a 40X magnification stereomicroscope, such effect can be seen clearly on the jade surface. Noting the chemical weathering changes and the tool marks left on the jade surface, makes identification possible. This site will deal into the amphibole chemical weathering process, and how to utilize it as one of the tools to authenticate antique Chinese jade. Chemical weathering changes on antique nephrite jade has only recently been looked into. Hopefully this blog can stimulate interest and discussion. All criticism and suggestions are welcome. Please send to my email address firstname.lastname@example.org
Jade is a beautiful gem stone. With its smooth luxurious texture, glossy semi transparent appearance, top it with a pleasant white or green color, jade has been part of the Chinese culture since the Neolithic time. From the very early on, it was regarded as a stone with mystic power and the medium of choice for religious expression. The association with religion also brought on the representation and association with power and wealth. This deep affection and the belief in the mystic power of jade linger on turning into thinking that jade cannot deteriorate even after several thousands years of burial. In a sense it is true. Jade pieces survive several thousands of years, much better than many other materials of the same period of time. But the deterioration is there if one looks. It is this deterioration that nature left on the jade surface that gives clues to the authenticity of the period the jade piece was carved. To understand these changes, one must know some fundamentals of the nephrite jade.
nephrite rich in iron
mutton fat nephrite, rich in magnesium .
nephrite rich in iron nephrite rich in magnisium
The two different types of jade are nephrite and jadeite. Jadeite is not native to China and did not come into China from Myanmar until the Ming dynasty. All jade pieces before the Ming dynasty are nephrite. Both jadeite and nephrite are minerals. Jadeite belongs to the pyroxene group, and nephrite belongs to the amphibole group. Both are inosilicate minerals, meaning they are silicate groups containing silicon and oxygen. They form prism or needle like crystals and contain iron and magnesium in their structure. Nephrite is a combination of two amphibole minerals, tremolite and actinolite in various ratio. Tremolite and actinolite are both calcium magnesium iron silicate with traces of sodium and aluminum. They share the same chemical formula, Ca²(Mg,Fe)5Si8O22(OH)², and similar physical properties with specific gravity of 2.95 (+.15, -.05). Both actinolite and tremolite have a hardness of Mosh scale 5.5 – 6, and nephrite has a Mosh scale 6 – 6.5. The color of tremolite are white, grey, black, yellow, green, pink and purple. The pink and purple varieties are mainly found in Lawrence county New York and are not found in China. Tremolite is white when there is more magnesium in its composition, and green when there is more iron. Iron is what gives the jade yellow to green color. Actinolite is iron rich with color of various shade of green to black. In nephrite, when the ratio of the magnesium rich tremolite is higher than the iron rich actinolite, it is white. Both of the above two samples are nephrite roughs. On the left is iron rich and green. On the right is magnesium rich and white. Today any nephrite with 90% magnesium rich tremolite, and therefore has a greasy white mutton fat color, is called Hetian regardless where it comes from.
Actinolite rough Tremolite rough
Minerals form crystals. The nephrite crystals are interlocking fibrous needles, bound together radiating out in a fan like fashion. The space between the bundles is the cleavage. which in nephrite is in two directions at about 60 and 120 degrees angles. The actinolite and tremolite specimens above show the crystal arrangement with the fibrous bundles radiating out. Because the crystals are bound tightly together interlacing, nephrite does not break easily. They are however easily cracked and separate at the cleavage. The interrelationship of the nephrite crystals are shown below in the scanning electron microscopy photos (Photos taken by Yi Bao https://www.gia.edu/gems-gemology/fall-2014-nephrite-jade-guangxi-province-china)
Rocks and minerals have a micro pore system, a system of minute openings on the surface between crystal and grain of the mineral. Pores extend down ward in pore throats, an interconnected passage way like channels that follow the cleavage of the mineral. Micro cracks also occur parallel or against the cleavage. The opening of these micro pores have a width of 1-2 μ. As weathering progress, the micro cracks widen to 5-10 μ. Water in the environment entering these micro pores and micro cracks, and reacting with the amphibole is the main aspect of chemical weathering. It is inside this system weathering changes take place. Below is a picture of the micro pores http://wiki.aapg.org/Pore_system_fundamentals. More details on the micro pore system can also be obtained from this link. http://wiki.aapg.org/Pore_systems
Gem minerals including nephrite form inside the crust of the Earth, with the only exceptions of peridot and diamond which form in the mantle. Under high temperature and pressure of the earth crust, nephrite is formed by metasomatism of dolomite by intrusive magmatic fluids, or silicic rocks by serpentinite fluids. This results in nephrite being encased in igneous and or metamorphic rocks, mixed with small amount of other minerals, diopside, magnetite, chromite, graphite, apatite, rutile, pyrite, datolite, vesuvianite, prehnite, garnet, talc and sphene. In China, nephrite from the Kunlun mountains are frequently associate with Pyroxene rocks, and those from the Karakash valley in Xinjiang province are frequently with Hornblende rocks. Thus nephrite are encased in other rocks making them difficult to identify. Nephrite in the primary deposit are deep underground, encased in rocks and therefore in general are not mined due to the expense of necessity to remove millions tons of rocks to obtain the mineral. With volcanic and tectonic activities, part of the primary deposit breaks off and uplifted to the surface from the crust to become the secondary deposit. There are two types of secondary deposit, eluvial and alluvial. As the deposit is pushed to the surface, weathering breaks down the hard encasing rocks and becomes a mount of debris with the mineral inside, forming the eluvial deposit. Nephrite mostly come from such mines probably exclusively before the Qing Dynasty. Within these mines nephrite are found encased within other minerals and rocks (坑玉). Identifying rocks that contain nephrite within can post challenges to nephrite miners and hunters.
Alluvial is when the primary or secondary deposit further erodes, broken off and finds its way tumbling down a river or stream. Way to obtain the mineral is usually by panning, as in panning for gold, or dredging in a larger scale mining. Minerals can also be found in dry up river beds. In such case hydraulic washing is the way to obtain them. Nephrite pebbles in rivers are found among similar size pebbles and rocks, making them unsuitable for panning. To mine such river pebbles traditionally in China, several people walk abreast, wading across the shallow river. As they wade across, they feels the pebbles on the river bed with their feet. Experience tells them which pebble to pick up for examination. However some believe that it is more accurate to say when wadding across they look down to pick up what looks like a nephrite pebble. River nephrite pebbles are less angular, smooth, polish and smaller due to constant rolling and tumbling in the stream. Most of the pebbles have areas of reddish and other discoloration called skin. The recent high demand of nephrite jade in China has basically exhausted the Xinjiang deposits. With unabated demands price of nephrite pebbles sky rocketed. Escalating high price brings out fake nephrite pebbles. How to identify the fake from the real nephrite pebbles becomes a problem. China in 2015 puts out a paper title “Identification Characteristics of Weathering Crust for Nephrite Gravel and its Imitation. Hui Li , Xuan Wang, Yong Zhu, Zhengyu Zhou. 5th International Conference on Information Engineering for Mechanics and Materials (ICIMM 2015)”.In the paper the authors identify three distinct points of difference between the nephrite pebbles natural weathering from the artificial applied changes.
Something resembling sweat pores are found on the surface of the natural weathered pebbles. These sweat pores are irregular, varied in shape and sizes, with some of these sweat pores connected, and some have smaller sweat pores within a larger one with the appearance of an island. These sweat pores are thought to come from collision with other pebbles and rocks in the stream. The artificial sweat pores are made from sand blasting, and the pores are uniform in size and shape with edges round and smooth, unlike the natural sweat pores.
Nail pattern formation on the natural weathered pebbles. These pattern are thought to be from the nephrite breaking from he primary deposit and collision in the stream. The artificial ones are more smooth and uniform.
Artificial color changes on the crust of the false nephrite pebbles are done by applying chemical on the surface, and hence they are brighter in color. Using ultraviolet-visible absorption spectroscopy, the absorption peak of the color changes on the natural nephrite pebbles show iron oxides F²-, F³-, whereas the applied color changes on the false pebbles do not contain any iron.
The sweat pores described by the authors are also seen on the buried nephrite jades. From the description, these should be etch pits result from natural chemical weathering, and not from the collision with other pebbles as stated. Nephrite is probably the hardest pebble in the stream. If they collide with other stones, they are more likely to crack than to chip. Weathering produces etch pits on nephrite surface with characteristics similar to what the paper describe. It is safe to say the pits found on the pebble are etch pits from weathering. It is hard to know what the authors refer to as the nail pattern. From the picture in the article, it seems to refer to the dendritic changes under the nephrite surface. The iron oxide formation is also seen in buried antique nephrite. Like all minerals and rocks, the nephrite pebbles also go through chemical weathering in nature. The three observations to identify the natural nephrite pebbles from the false ones are similar to the observations used to identified the burial nephrite jade from the fake ones. These surface changes are the result of natural chemical weathering of amphibole which we are going to explore next.