Image: <a rel="nofollow" class="external text" href="https://www.flickr.com/people/47445767@N05">James St. John</a> (CC BY 2.0)
monoclinicuncommonSilicates (Amphibole group)
Nephrite Jade
Ca2(Mg,Fe)5Si8O22(OH)2 (Tremolite-Actinolite series)
This specimen is a dark green, ventifacted piece of nephrite jade, showing a smooth, weathered surface. Nephrite jade is a tough, dense metamorphic rock with a fine-grained, felted texture.
Nephrite Jade Physical Properties
Mohs Hardness
6Crystal System
monoclinicLuster
vitreousStreak Color
whiteCleavage
None (due to felted texture, though constituent amphiboles have perfect cleavage)Fracture
splintery to fibrousSpecific Gravity
2.95Colors
green, white, yellow, brown, blackTransparency
translucent to opaqueType Locality
Granite Mountains, Wyoming, USAMineral Group
Silicates (Amphibole group)Uses
jewelry, carvings, tools, collectorAssociated Minerals
serpentine, chlorite, talc, magnetite, chromiteRarity
uncommonGeological Context
Nephrite jade is a metamorphic rock, primarily composed of tremolite-actinolite amphiboles, formed under high pressure and low temperature conditions, often associated with serpentinization. This specimen is from the Precambrian era in Wyoming, USA.
