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In 1863, a French mineralogist, Alexis Damour, analyzed the bright green stones from Burma. Finding them different from ordinary Chinese jade (nephrite), he named the "new" jade, jadeite. Today, gemologists apply the term jade only to nephrite and jadeite. Nephrite is a fibrous subspecies of the actinolite tremolite series, while jadeite is a member of the pyroxene mineral group. The ideal composition of jadeite is [NaAl(SiO3)2], but it is frequently mixed with diopside [CaMg(SiO3)2] or acmite [NaFe(SiO3)2]. Jadeite rich in iron (mixed with acmite) is a dark green to black color and is termed chloromelanite.
Lapidaries and jewelers should constantly attempt to call gemstones and rough material by their correct name. Jade has many other stones named after it, as any material. The confusion as to what jade is, has been compounded by this deceptive practice.
Amazon jade is adventurine, American jade is a rock - a mixture of idocrase and grossular, Australian jade is chrysophrase, Colorado jade is green microcline, Flukien, Manchurian, and Honan jade are all soapstone, Indian jade is adventurine, Jadite is pure jade. (editor's note ? - not sure what that means), Jasper jade is green jasper, Korean jade is bowenite, a hard variety of serpentine. Mexican jade is green dyed marble or calcite, Oregon jade is a dark green jasper, Silver Peak jade is malachite, Transvall jade is a massive variety of green grossular garnet, Real jade such as BC jade, Alaska or Yukon jade are truly nephrite jade.
Nephrite Hardness: 6-61/2 S.G. 2.95 R.I. 1.6 2.63
Jadeite Hardness: 61/2-7 S.G. 3.3 R.I. 1.66 - 1.68
Identifying jade:
1. If you chip the edge of a suspected specimen and it sparkles or glitters, it's not jade.
2. If you can scratch it with a knife blade, it's not jade.
3. It should be much heavier than a common rock of similar size.
4. Tap The specimen lightly with the point of your pick. If a small moon-shaped fracture shows up, it is agate or jasper, but not jade. If it is jade, it will have a smooth, waxy, almost greasy, look and feel.
Jade comes in many different colors not just green. Lavender, black and motled or spotted varieties such as brown with yellow and orange, red with shades of green and purple are also known and are very highly coveted for carvings or artistic lapidary works. When one speaks of value, concerning jade. It is it's luster, color and transperancy that determines it's price.
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