Image: <a rel="nofollow" class="external text" href="https://www.flickr.com/people/47445767@N05">James St. John</a> (CC BY 2.0)
monocliniccommonSilicates
Jade
Ca₂(Mg,Fe)₅Si₈O₂₂(OH)₂
This specimen is a large, irregularly shaped piece of nephrite jade, displaying a mottled appearance with shades of dark green, yellowish-green, and brownish tones, and a somewhat rough, ventifacted surface.
Jade Physical Properties
Mohs Hardness
6Crystal System
monoclinicLuster
vitreousStreak Color
whiteCleavage
good in two directions at ~56° and 124° (for constituent amphiboles)Fracture
splinterySpecific Gravity
3Colors
dark green, yellowish-green, brownish-greenTransparency
translucentType Locality
Granite Mountains, Wyoming, USAMineral Group
SilicatesUses
jewelry, carving, ornamental objects, collectorAssociated Minerals
tremolite, actinoliteRarity
commonGeological Context
Nephrite jade is a metamorphic rock formed from the alteration of ultramafic rocks or dolomitic limestones under high pressure and relatively low temperature conditions, typically found in subduction zones or regional metamorphic terrains. This specimen is from the Precambrian of Wyoming.
