metamorphic
Polished nephrite jade
Nephrite jade — interlocking amphibole, chiefly tremolite–actinolite, Ca₂(Mg,Fe)₅Si₈O₂₂(OH)₂
AI-generated identification · may be incorrectTypically Mohs 6–6.5; dark green to black with a waxy-to-greasy luster and fine, fibrous interlocking crystal structure. The specimen appears polished, with pale green veining and strong translucency only at thin edges; cleavage is indistinct and toughness is exceptionally high.
Identified More metamorphic →
Explore Polished nephrite jade in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Typically Mohs 6–6.5; dark green to black with a waxy-to-greasy luster and fine, fibrous interlocking crystal structure. The specimen appears polished, with pale green veining and strong translucency only at thin edges; cleavage is indistinct and toughness is exceptionally high.
Formation & geological history
Forms when magnesium-rich rocks undergo metamorphism and hydrothermal alteration, commonly in serpentinite-associated zones. Nephrite deposits range from Paleozoic to Cenozoic ages and occur in tectonic mountain belts.
Uses & applications
Used for carvings, beads, cabochons, ornaments, and durable tools; high-quality material is valued in jewelry and cultural art. Common dark or heavily veined pieces generally have modest commercial value.
Geological facts
Nephrite is one of the two materials historically called jade; the other is jadeite. Its toughness comes from densely interwoven amphibole fibers rather than exceptional hardness.
Field identification & locations
Commonly found in New Zealand, British Columbia, Wyoming, Siberia, Taiwan, and China. Field clues include unusual toughness, a smooth waxy polish, fibrous texture, and green color; visual identification alone cannot reliably distinguish it from serpentine or other green stones.
More like this
