Jade Jade HMS Good Hope (1901) Category="Gemstones"Category="Silicate minerals"
For other uses, see Jade (disambiguation).

[image] [image] 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 .

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.

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 Yang Ze 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 verdātre, Feitsui, Jadeit, Jadeita, Natronjadeit, Yunnan Jade, Yu-stone

Nephrite

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 Jade

In Asian culture, wearing jade is considered to bring good luck.

Faux Jade

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. "Korean jade," "Suzhou jade," "Styrian jade," "Canadian jade," "Olive jade" and "New jade" are all really serpentine; "Transvaal jade" is grossularite. Other names for fake jade are: "Honan jade," "Metajade" and "Sinkiang jade."

Real jade may be enhanced (sometimes call "stabilized"). There are three main methods, sometimes referred to as the ABC Treatment System:

Type A treatment is the only acceptable enhancement by professional collectors.

See also

Further Reading

External links