(jadeite) buttons]]
Jade is an ornamental stone.
The term
jade is applied to two different
metamorphic rocks that are made up of different
silicate minerals:
Nephrite consists of a microcrystaline interlocking fibrous matrix of the calcium, magnesium-iron rich amphibole mineral series tremolite (calcium-magnesium)-ferroactinolite (calcium-magnesium-iron). The middle member of this series with an intermediate composition is called actinolite (the silky fibrous mineral form is one form of asbestos). The higher the iron content the greener the colour.
Jadeite is a sodium- and aluminium-rich pyroxene. The gem form of the mineral is a microcrystaline interlocking crystal matrix.
Etymology
The English word
jade (alternative spellings "jaid", "jadeite") is derived (via French
l'ejade and Latin
ilia) from the Spanish term
piedra de ijada (first recorded in 1565) or "loin stone", from its reputed efficacy in curing ailments of the
loins and
kidneys.
Nephrite is derived from
lapis nephriticus, the Latin version of the Spanish
piedra de ijada.
Overview
Nephrite versus jadeite
Nephrite and jadeite were used from
prehistoric periods for
hardstone carving. Jadeite has about the same
hardness as quartz, while nephrite is somewhat softer. Both nephrite and jadeite are
tough, but nephrite is tougher than jadeite. It was not until the 19th century that a French mineralogist determined that "jade" was in fact two different materials. The
trade name jadite (not to be confused with
jadeite) is sometimes used for translucent or opaque green glass.
Among the earliest known jade artifacts excavated from prehistoric sites are simple ornaments with bead, button, and tubular shapes. Additionally, jade was used for axe heads, knives, and other weapons, which can be delicately shaped. As metal-working technologies became available, the beauty of jade made it valuable for ornaments and decorative objects. Jadeite measures between 6.5 and 7.0 Mohs hardness, and Nephrite between 5.5 and 6.0, so it can be worked with quartz or garnet sand, and polished with bamboo or even ground jade.
Unusual varieties
Nephrite can be found in a creamy white form (known in China as "mutton fat" jade) as well as in a variety of green colours, whereas jadeite shows more colour variations, including blue, lavender-mauve, pink, and emerald-green colours. Of the two, jadeite is rarer, documented in fewer than 12 places worldwide. Translucent emerald-green jadeite is the most prized variety, both today and historically. As "quetzal" jade, bright green jadeite from
Guatemala was treasured by
Mesoamerican cultures, and as "kingfisher" jade, vivid green rocks from Burma became the preferred stone of post-1800 Chinese imperial scholars and rulers. Burma (
Myanmar) and Guatemala are the principal sources of modern gem jadeite, and Canada of modern lapidary nephrite. Nephrite jade was used mostly in pre-1800
China as well as in
New Zealand, the Pacific Coast and Atlantic Coasts of North America, Neolithic Europe, and south-east Asia. In addition to Mesoamerica, jadeite was used by Neolithic Japanese and European cultures.
History
Prehistoric and historic China
(
202 BC –
9 AD)]]
During
Neolithic times, the key known sources of nephrite jade in China for utilitarian and
ceremonial jade items were the now depleted deposits in the Ningshao area in the
Yangtze River Delta (
Liangzhu culture 3400–2250 BC) and in an area of the
Liaoning province and
Inner Mongolia (
Hongshan culture 4700–2200 BC). As early as 6000 BC Dushan Jade was being mined. In the Yin Ruins of the Shang Dynasty (1600 BC to 1050 BC) in Anyang, Dushan Jade ornaments were unearthed in the tomb of the Shang kings. Jade was used to create many utilitarian and ceremonial objects, from indoor decorative items to
jade burial suits. Jade was considered the "imperial gem". From the earliest
Chinese dynasties to the present, the jade deposits most in use were not only those of
Khotan in the Western Chinese province of
Xinjiang but other parts of China as well, such as Lantian,
Shaanxi. There, white and greenish nephrite jade is found in small quarries and as pebbles and boulders in the
rivers flowing from the
Kuen-Lun mountain range eastward into the
Takla-Makan desert area. The river jade collection is concentrated in the
Yarkand, the White Jades
(
Yurungkash) and Black Jade (
Karakash) Rivers. From the
Kingdom of Khotan, on the southern leg of the
Silk Road, yearly tribute payments consisting of the most precious white jade were made to the Chinese Imperial court and there worked into
objets d'art by skilled artisans as jade had a status-value exceeding that of
gold or
silver. Jade became a favorite material for the crafting of Chinese scholars' objects, such as rests for calligraphy brushes, as well as the mouthpieces of some
opium pipes, due to the belief that breathing through jade would bestow longevity upon smokers who used such a pipe.
Jadeite, with its bright emerald-green, pink, lavender, orange and brown colours was imported from Burma to China only after about 1800. The vivid green variety became known as Feicui (翡翠) or Kingfisher (feathers) Jade. It quickly replaced nephrite as the imperial variety of jade.
In the history of the art of the Chinese empire, jade has had a special significance, comparable with that of gold and diamonds in the West. Jade was used for the finest objects and cult figures, and for grave furnishings for high-ranking members of the imperial family.
Prehistoric and historic India
The
Jainist temple of
Kolanpak in the
Nalgonda district,
Andhra Pradesh,
India is home to a high
sculpture of
Mahavira that is carved entirely out of jade. It is the largest sculpture made from a single jade rock in the world.
Prehistoric and early historic Korea
with comma-shaped jades, was excavated from the
Heavenly Horse Tomb of
Silla and dates to the 5th century AD.]]
The use of jade and other greenstone was a long-term tradition in
Korea (c. 850 BC – AD 668). Jade is found in small numbers of
pit-houses and
burials. The craft production of small
comma-shaped and tubular "jades" using materials such as jade,
microcline,
jasper, etc., in southern Korea originates from the Middle
Mumun Pottery Period (c. 850–550 BC). Comma-shaped jades are found on some of the gold crowns of
Silla royalty (c. AD 300/400–668) and sumptuous
elite burials of the
Korean Three Kingdoms. After the state of Silla united the Korean Peninsula in AD 668, the widespread popularisation of death rituals related to
Buddhism resulted in the decline of the use of jade in burials as prestige mortuary goods.
Māori
Nephrite jade in
New Zealand is known as
pounamu in the
Māori language (often called "greenstone" in
New Zealand English) which plays an important role in
Māori culture. It is considered a
taonga, or treasure, and therefore protected under the
Treaty of Waitangi, and the exploitation of it is restricted and closely monitored. It is found only in the
South Island of New Zealand, known as
Te Wai Pounamu in
Māori—"The [land of] Greenstone Water", or
Te Wahi Pounamu—"The Place of Greenstone".
Tools, weapons and ornaments were made of it; in particular adzes, the 'mere' (short club), and the Hei-tiki (neck pendant). These were believed to have their own mana, handed down as valuable heirlooms, and often given as gifts to seal important agreements. Nephrite jewellery of Maori design is widely popular with locals and tourists, although some of the jade used for these is now imported from British Columbia and elsewhere.
Mesoamerica
from the
Mayan Classic period ( high)]]
Jade was a rare and valued material in
pre-Columbian Mesoamerica. The only source from which the various
indigenous cultures, such as the
Olmec and
Maya, could obtain jade was located in the
Motagua River valley in
Guatemala. Jade was largely an
elite good, and was usually carved in various ways, whether serving as a medium upon which
hieroglyphs were inscribed, or shaped into
symbolic
figurines. Generally, the material was highly symbolic, and it was often employed in the performance of
ideological practices and
rituals.
Faux jade
The term faux jade is a misnomer, at best. A stone can be readily identified as either a jadeite or nephrite gemstone by a specialized jade dealer. As most jewelers have little or sparse knowledge about jade, jade should only be purchased from vendors who specialize in jade. Unlike the diamond industry, which has a central recognized authority that controls price and availablity, known as DeBeers, there is no such recognized authority for other gemstones. As a result, stones represented as jade, even in high end jewelry stores, may often reflect poor quality or color treatment to enhance appearance, and are priced at the same level as other high-end jewlery, such as diamonds and gold, not in any way commensurate with the quality of the jade stone being represented. As a result, many minerals are sold as jade. Some of these are:
serpentine (also bowenite),
carnelian,
aventurine quartz,
glass,
grossularite,
Vesuvianite,
soapstone (and other
steatites such as shoushan stone) and recently, Australian
chrysoprase. "Suzhou jade," "Styrian jade," "Olive jade", and "New jade" are all really serpentine; "Transvaal jade" or "African jade" is grossularite; "Peace jade" is a mixture of serpentine, stichtite, and quartz; "Mountain jade" is dyed dolomite marble.
Unlike the typical high end jeweler, specialized jade dealers can provide the scientific name of specific "jade" stones upon request, although the high-end jewelers' clerks who sell faux jades may be unaware that multiple types of stone are sold under that name.
Confusion in Chinese and Korean about jade as opposed to other precious stones
In almost all dictionaries, the Chinese character
yù (玉) is translated into English as "jade". However, this frequently leads to misunderstanding: Chinese, Koreans, and Westerners alike generally fail to appreciate that the cultural concept of jade is considerably broader in China and Korea than in the West. A more accurate translation for this character on its own would be "precious/ornamental rock". It is seldom if ever used on its own to denote "true" jade in Mandarin Chinese; for example, one would normally refer to
ying yu (硬玉, "hard jade") for jadeite, or
ruan yu (軟玉, "soft jade") for nephrite. The Chinese names for many ornamental non-jade rocks also incorporate the character
yù, and it is widely understood by native speakers that such stones are not, in fact, true precious nephrite or jadeite. Even so, for commercial reasons, the names of such stones may well still be translated into English as "jade", and this practice continues to confuse the unwary.
Enhancement
Jade may be enhanced (sometimes called "stabilized"). Note that some merchants will refer to these as Grades, but it is important to bear in mind that degree of enhancement is different from colour and texture quality. In other words, Type A jadeite is not enhanced but can have poor colour and texture. There are three main methods of enhancement, sometimes referred to as the ABC Treatment System:
Type A jadeite has not been treated in any way except surface waxing.
Type B treatment involves exposing a promising but stained piece of jadeite to chemical bleaches and/or acids and impregnating it with a clear polymer resin. This results in a significant improvement of transparency and colour of the material. Currently, infrared spectroscopy is the most accurate test for the detection of polymer in jadeite.
Type C jade has been artificially stained or dyed. The effects are somewhat uncontrollable and may result in a dull brown. In any case, translucency is usually lost.
B+C jade is a combination of B and C: it has been both artificially dyed AND impregnated.
Type D jade refers to a composite stone such as a doublet comprising a jade top with a plastic backing.
Gallery of Chinese jades
See also
Jade burial suit
Mumun Pottery Period, the time in Korea when jade ornament production began
Heavenly Horse Tomb, a Silla royal tomb in Korea with jade artifacts.
Pounamu
Notes
References
Scott-Clark, Cathy and Levy, Adrian. (2002) The Stone of Heaven: Unearthing the Secret History of Imperial Green Jade. ISBN 0316525960
Further reading
Laufer, Berthold, 1912, Jade: A Study in Chinese Archeology & Religion, Reprint: Dover Publications, New York. 1974.
Rawson, Jessica, 1975, Chinese Jade Throughout the Ages, London: Albert Saifer, ISBN 0-87556-754-1
Jadeite sources in Mesoamerica (PDF)
Between hell and the Stone of Heaven: Observer article on Jade Mining in Burma
Old Chinese Jades: Real or Fake?
BOOK REVIEW, The Stone of Heaven: The Secret History of Imperial Green Jade by Adrian Levy and Cathy Scott-Clark
External links
The British Museum - 7,000 years of Chinese jade
Gravity Measurement For Testing Jade (2008 archived version)
mindat.org (Mineralogical data about Jade)
Jade in Canada
"Jade in British Columbia table", BC Govt MINFILE summary of jade showings and producers
Canadian Rockhound magazine feature on jade
"Guatemalan Jadeite", Precolumbian Replicas and Fine Jewelry
Category:Chinese culture
Category:Gemstones
Category:Provincial symbols of British Columbia
Category:Inosilicates
Category:Hardstone carving
Category:Shades of green
