metamorphic
Polished dark green stone, likely nephrite jade
Nephrite jade (interlocking tremolite–actinolite amphibole, Ca₂(Mg,Fe)₅Si₈O₂₂(OH)₂)
AI-generated identification · may be incorrectTypically Mohs hardness 6–6.5, exceptionally tough, with dark green color, waxy to greasy luster, and fine interlocking fibrous crystals; cleavage is poor or indistinct. The smooth surface indicates polishing or natural water-wear.
Identified More metamorphic →
Explore Polished dark green stone, likely nephrite jade in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Typically Mohs hardness 6–6.5, exceptionally tough, with dark green color, waxy to greasy luster, and fine interlocking fibrous crystals; cleavage is poor or indistinct. The smooth surface indicates polishing or natural water-wear.
Formation & geological history
Forms by metamorphism and metasomatism of magnesium-rich rocks, commonly in serpentinite belts; major sources include British Columbia, Wyoming, Siberia, New Zealand, and China. Exact age and locality cannot be determined from the photograph.
Uses & applications
Used for carvings, tools, ornaments, beads, and jewelry; its toughness makes it especially valuable for sculpture. Quality depends on translucency, even color, texture, size, and provenance.
Geological facts
Nephrite is one of the two jade varieties, the other being jadeite. It is generally tougher but less hard than jadeite and may contain black chromite or magnetite inclusions.
Field identification & locations
Field clues include unusually high toughness, dense feel, greasy luster, and a fine, non-granular texture; it should resist scratching from a steel knife but not quartz. Definitive identification requires hardness, density, microscopy, or spectroscopy.
More like this
