Nephrite
Variety Ca2(Mg,Fe)5Si8O22(OH)2
Also called Nephrite jade, BC jade, and Pounamu
About it
The commoner jade: a felt of interlocking amphibole fibres that makes it one of the toughest stones. British Columbia is a major producer, and New Zealand pounamu and Chinese carvings are classic.
- Type
- Variety
- Group
- Tremolite-actinolite variety (amphibole)
- Formula
- Ca2(Mg,Fe)5Si8O22(OH)2
- Hardness (Mohs)
- 6–6.5
- Specific gravity
- 2.9–3.1
- Streak
- white
- Lustre
- greasy, vitreous (glassy)
- Crystal system
- Monoclinic
- Colours
- spinach green, dark green, white, cream, grey, black
- Transparency
- translucent, opaque
- Cleavage and fracture
- none in massive form; very tough, splintery fracture
Typical values: real specimens vary. For more, see mindat.org.