Image: <a rel="nofollow" class="external text" href="https://www.flickr.com/people/47445767@N05">James St. John</a> (CC BY 2.0)
monoclinicuncommonSilicates
Nephrite Jade
Ca2(Mg,Fe)5Si8O22(OH)2
A black, dense, and tough metamorphic rock, exhibiting a smooth, wind-eroded surface (ventifact). It has a fine-grained, felted texture.
Nephrite Jade Physical Properties
Mohs Hardness
6Crystal System
monoclinicLuster
vitreousStreak Color
whiteCleavage
good in two directions at ~56° and ~124°Fracture
splinterySpecific Gravity
2.95Colors
black, green, white, yellow, brownTransparency
translucentType Locality
Granite Mountains, Wyoming, USAMineral Group
SilicatesUses
carving, jewelry, tools, ornamental stoneAssociated Minerals
tremolite, actinoliteRarity
uncommonGeological Context
Formed during the Precambrian era through regional metamorphism of ultramafic rocks or dolomitic limestones, resulting in a dense, interlocking fibrous aggregate of amphibole minerals. The specimen itself is a ventifact, shaped by wind erosion.
