metamorphic

Tumbled greenstone (likely serpentine or nephrite jade)

Serpentine-group mineral, commonly antigorite [(Mg,Fe)₃Si₂O₅(OH)₄], or nephrite jade (interlocking tremolite–actinolite amphibole)

AI-generated identification · may be incorrect

Opaque to slightly translucent olive-green stone with waxy to vitreous luster and rounded tumbled form. Serpentine has Mohs hardness 2.5–4; nephrite is tougher and about 6–6.5; no diagnostic crystal faces are visible.

Identified September 5, 2026More metamorphic →

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At a glance

Common name: Tumbled greenstone (likely serpentine or nephrite jade)
Scientific name: Serpentine-group mineral, commonly antigorite [(Mg,Fe)₃Si₂O₅(OH)₄], or nephrite jade (interlocking tremolite–actinolite amphibole)
Category: metamorphic
Identified: September 5, 2026
Method: Standard

AI Estimated Value

About $2–$15 for common tumbled serpentine; approximately $10–$100+ for quality nephrite pieces, depending on color, translucency, size, and provenance.

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

Serpentine forms when ultramafic mantle rocks undergo hydration and alteration; nephrite forms through metamorphism of magnesium-rich rocks. These are generally Phanerozoic geologic materials, though exact age is locality-dependent.

Uses & applications

Used for carvings, ornaments, lapidary pieces, and decorative stone; true nephrite jade can have significant jewelry value, while common serpentine is inexpensive.

Geological facts

The image alone cannot reliably distinguish serpentine from jade; laboratory hardness, specific gravity, refractive index, and microscopy are useful.

Field identification & locations

Look for mottled olive-green color, waxy luster, and softness for serpentine; nephrite is notably dense, fibrous, and exceptionally tough. Common sources include New Zealand, China, Canada, Russia, Italy, and the United States.