metamorphic

Polished greenstone (likely nephrite jade)

Nephrite, an interlocking fibrous aggregate of amphibole-group minerals, chiefly tremolite–actinolite, Ca₂(Mg,Fe)₅Si₈O₂₂(OH)₂

AI-generated identification · may be incorrect

Hardness about 6–6.5 Mohs; dark olive-green to gray-green, vitreous to greasy luster, opaque, and exceptionally tough. The elongated groove and smooth glossy surface indicate a polished or tumbled specimen.

Identified September 21, 2026More metamorphic →

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At a glance

Common name: Polished greenstone (likely nephrite jade)
Scientific name: Nephrite, an interlocking fibrous aggregate of amphibole-group minerals, chiefly tremolite–actinolite, Ca₂(Mg,Fe)₅Si₈O₂₂(OH)₂
Category: metamorphic
Identified: September 21, 2026
Method: Standard

AI Estimated Value

About $10–$50 for a small common polished piece; $100–$500+ for attractive, authenticated, high-quality nephrite.

Not an official valuation

AI estimate for general interest only — not an appraisal. Actual value depends on condition, provenance, and market demand. Verify with a professional before buying, selling, or insuring.

This identification was generated by AI and may contain errors. Verify important details before relying on them — and never use an AI result to judge whether a specimen is safe to handle. Read the full disclaimer

Physical properties

Formation & geological history

Forms when magnesium-rich rocks undergo metamorphism and fluids promote amphibole growth, commonly in subduction-related serpentinite zones. Nephrite deposits are generally Paleozoic to younger, depending on locality.

Uses & applications

Used for carvings, beads, cabochons, ornaments, and historically tools or weapons; its toughness makes it valuable for durable art objects rather than faceted gems.

Geological facts

Nephrite is one of the two materials traditionally called jade, the other being jadeite. Its felted amphibole fibers resist breaking and can produce a waxy polish.

Field identification & locations

Identify by its dense feel, waxy polish, fibrous texture under magnification, and resistance to scratching; common sources include British Columbia, Wyoming, Siberia, New Zealand, and China. Confirm with hardness, specific gravity, and gemological testing because serpentine and other greenstones can look similar.