Jadeite

Color: Brown, blackish, violet, green, also white, reddish, yellow
Color of streak: White
Mohs’ hardness: 6.5 – 7
Specific gravity: 3.30 – 3.36
Cleavage: Imperfect
Crystal system: Monoclinic ; inter-grown, grainy and fine fibrous aggregate
Chemical composition: sodium aluminium silicate
Transparency: Opague, translucent
Refractive index: 1.654 – 1.667
 

The name derives from jade (piedra de ijada), i.e. hip stone in Spanish as it was seen as a protection against and cure for kidney diseases). Because of its fibrous, felt-like structure, it is very tough and resistance. It occures in all colors.  Fractures are dull and when polished, greasy, sometimes in pearly luster. Most valuable is the imperial jade, an emerald green translucent jadeite from Burma, with chrome as pigment. 

The most important jadeite deposits are in Burma, near Tawmav, interlayered in serpentinite, or in secondary deposits in conglomerates or in river gravels. The material found here is exported to China. Other deposits are in China, Guatamala, Japan, Mexico and the US (California).

Chloromelanite: Green-black speckled variety of jadeite.

Jade-albite: composite of albite feldspar and jadeite from upper Burma, strong green with black spots.