An ornamental stone, jade is a name applied to two different silicate minerals. Nephrite is a form of the amphibole actinolite (a mineral that also includes a form of asbestos). The second, the mineral jadeite, is a pyroxene. Nephrite has the formula Ca2(Mg, Fe)5Si8O22(OH)2. Jadeite has the formula NaAlSi2O6. The two are quite similar in appearance and it wasn't until 1863 that the two forms of this gemstone were distinguished.
It is an exceptionally tough material, and was first used for things such as axe heads, knives, and weapons. Later, as other materials could replace jade as a weapons material, it became appreciated for its beauty. Jade has a Mohs hardness of between 6.5 and 7.0 http://www.orionsgemz.com/Mohs.html.
Nephrite can be found in a creamy white form as well as a green color, while jadeite shows more color variation. Of the two, jadeite is rarer, and is the form of jade mostly used in Central America. Nephrite jade was used mostly in China, Myanmar and New Zealand.
Jade is the official gemstone of British Columbia, where it is found in large deposits in the Lillooet and Cassiar regions.
History
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 jade culture 3400–2250 BC) and in an area of the Liaoning province in Inner Mongolia (Hongshan culture 4700–2200 BC). Jade was used to create many utilitarian and ceremonial objects, ranging from indoor decorative items to jade burial suits. From about the earliest Chinese dynasties until present, the jade deposits in most use were from the region of Khotan in the Western Chinese province of Xinjiang. 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 northward into the Takla-Makan desert area. River jade collection was concentrated in the Yarkand, the White Jade(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 transformed into ''objets d'art by skilled artisans as jade was considered more valuable than gold or silver.
Jadeite with its bright emerald-green, pink, lavender and brown colors was imported from Burma to China only after the 17th century and became known as Feitsu or Kingfisher (feathers) Jade.
In New Zealand, where it is known as greenstone or pounamu, nephrite was fashioned for centuries by Maori to make weapons and ornaments, and is still widely used to make carved jewellery although the mining of it is restricted and closely monitored.
Other Names
Besides the terms already mentioned, jadeite and nephrite are sometimes referred to by the following:Jadeite
Agate verdâtre, Feitsui, Jadeit, Jadeita, Natronjadeit, Yunnan Jade, Yu-stone, Sinkiang jadeNephrite
Aotea, Axe-stone, B.C. Jade, Beilstein, Grave Jade, Kidney Stone, Lapis Nephriticus, Nephrit, Nephrita, Nephrite (of Werner), New Zealand Greenstone, New Zealand Jade, Spinach Jade, Talcum Nephriticus, Tomb JadeIn Asian culture, wearing jade is considered to bring good luck.
Chinese Jade -
yuMany minerals are sold as jade in China. 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. "Korean jade," "Suzhou jade," "Styrian jade," "Canadian jade," "Olive jade" and "New jade" are all really serpentine; "Transvaal jade" is grossularite. Other names for jade in China are: "Honan jade," "Metajade" and "Xinjiang jade."Jade may be enhanced (sometimes call "stabilized"). There are three main methods, 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 color of the material. Currently, infrared spectroscopy is the only test for the detection of polymer in jadeite.
*Type C jade has been artificially stained or dyed. The red color of Red jade can be enhanced with heat. The effects are somewhat uncontrollable and may result in a dull brown. In any case, translucency is usually lost.
Type A treatment is the only acceptable enhancement by professional collectors.
See also
*jade burial suit*Jade Emperor in Chinese mythology
*jade (color)
Further Reading
*Laufer, Berthold, 1912, Jade: A Study in Chinese Archaeology & Religion, Reprint: Dover Publications, New York. 1974.*Rawson, Jessica, 1975, Chinese Jade Throughtout the Ages, London: Albert Saifer, ISBN 0875567541
External links
*Jade*Jade: Chinese Stone of Heaven
*ancient chinese jade
*mindat.org
*Jade in Canada
Category:Silicate minerals
Category:Gemstones
In the history of cryptography, JADE was the codename given by US codebreakers to a Japanese cipher machine. The Imperial Japanese Navy used the machine for communications from late 1942 until 1944. JADE was similar to another cipher machine, CORAL, with the main difference that JADE was used to encipher messages in katakana using an alphabet of 50 symbols.
See also
* PURPLE* RED
External links
* TENTATIVE LIST OF ENIGMA AND OTHER MACHINE USAGES 30 March 1945 — JADE is coveredCategory:Encryption devices
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Jade is the common name for a green-colored gemstone of nephrite or jadeite.
Jade may also mean:
People
* Jade Villalon, singer of Sweetbox.* Jade Raymond, a TV personality.
Fictional characters
* Jade (Mortal Kombat character), a Mortal Kombat character.* Jade (comics), Jennie-Lynn Hayden-Scott, the superpowered daughter of Green Lantern Alan Scott from DC Comics.
* Jade (chaos comics), A female vampire from Chaos Comics.
* Mara Jade, a Star Wars character
* Jade, the heroine of the computer game Beyond Good & Evil
* Jade, an Indigo Child whose finding is the main objective in the computer game Fahrenheit''
In culture
* Jade (film), a 1995 William Friedkin film.* Jade (UK band), an English folk rock band from 1970.
* Jade (US band), an American R&B music group from the 1990s.
* Jade Emperor, an important Taoist god.
Geographical
* A large inlet on the north coast of Germany east and northeast of Wilhelmshaven: see Jadebusen.* Jade (river), a small river that drains into the Jadebusen
* Jade (municipality), a municipality located at the Jadebusen
* Jade, a small city located at the river Jade and in the Jade municipality
Other meanings
* JADE, European Confederation of Junior Enterprises.* Jade plant, a type of plant.
* JADE, the American codename for a Japanese cipher machine.
* JADE, an ADOM roguelike.
* JADE programming language.
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