An ornamental stone,
jade is a name applied to two related
minerals, the
nephrite form of
actinolite (a mineral that also includes a form of
asbestos), and a mineral called
jadeite. The former is a calcium magnesium iron silicate hydroxide, with the formula Ca
2(Mg, Fe)
5Si
8O
22(OH)
2, and the latter is a sodium aluminum silicate, with the formula NaAlSi
2O
6. The two are closely related, and it wasn't until 1863 that people could distinguish between the two forms of this stone.
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.
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.
Jade is the official gemstone of British Columbia.
External References
- Jade (http://mineral.galleries.com/minerals/gemstone/jade/jade.htm)
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