metamorphic

Tumbled green stone, likely serpentine or nephrite jade

Serpentine-group minerals, commonly antigorite [(Mg,Fe)₃Si₂O₅(OH)₄]; visual identification is uncertain

AI-generated identification · may be incorrect

Dark green-gray, mottled, opaque, and waxy to vitreous with a smooth polish; likely hardness Mohs 3–6, poor cleavage, and specific gravity about 2.5–3.3. The rounded form indicates tumbling or polishing.

Identified August 16, 2026More metamorphic →

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At a glance

Common name: Tumbled green stone, likely serpentine or nephrite jade
Scientific name: Serpentine-group minerals, commonly antigorite [(Mg,Fe)₃Si₂O₅(OH)₄]; visual identification is uncertain
Category: metamorphic
Identified: August 16, 2026
Method: Standard

AI Estimated Value

Approximately $2–$15 as common serpentine; $20–$100+ if verified as quality nephrite jade.

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 rocks are hydrated during metamorphism, commonly in oceanic crust and subduction-zone environments; ages vary widely from Precambrian to modern tectonic settings. Nephrite jade is a tougher interlocking amphibole aggregate and is a possible alternative.

Uses & applications

Used for carvings, beads, cabochons, ornaments, and decorative stone; higher-quality nephrite can be valuable in jewelry and sculpture. Serpentine is also used as an ornamental and architectural stone.

Geological facts

Serpentine commonly shows cloudy green color, dark veining, and a waxy feel; nephrite is typically tougher and more uniformly fibrous. A scratch test, specific gravity, and microscopic examination are needed for confident separation.

Field identification & locations

Common in serpentinite belts worldwide, including California, New Zealand, Canada, Russia, and Italy. Value is usually $2–$15 for a small common tumbled piece, or $20–$100+ if confirmed as attractive jade.