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
A black, felted-textured metamorphic rock primarily composed of amphibole minerals from the tremolite-actinolite series, known for its exceptional toughness.
Nephrite Jade Physical Properties
Mohs Hardness
6Crystal System
monoclinicLuster
vitreousStreak Color
whiteCleavage
Good in two directions at ~56° and ~124° (for constituent amphiboles, but rarely observed in massive nephrite)Fracture
splintery, tough, sometimes conchoidalSpecific Gravity
2.95Colors
black, green, white, yellow, brownTransparency
translucent to opaqueType Locality
Central Wyoming, USAMineral Group
Silicates (Amphibole Group)Uses
jewelry, carving, ornamental objects, toolsAssociated Minerals
Rarity
uncommonGeological Context
Nephrite jade forms under regional metamorphism, typically from ultramafic rocks or dolomitic limestones, often found in ancient terrains like the Precambrian of Wyoming.
