metamorphic

Tumbled serpentine (likely green calcite or aventurine alternative)

Serpentine-group minerals, commonly antigorite/lizardite; approximate formula Mg₃Si₂O₅(OH)₄

AI-generated identification · may be incorrect

Pale yellow-green, opaque to slightly translucent, waxy/glassy luster, rounded from tumbling; hardness about 2.5–4 Mohs, with no visible cleavage and typically massive rather than crystalline. The photograph alone cannot distinguish serpentine confidently from green calcite, jade, or aventurine.

Identified September 12, 2026More metamorphic →

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At a glance

Common name: Tumbled serpentine (likely green calcite or aventurine alternative)
Scientific name: Serpentine-group minerals, commonly antigorite/lizardite; approximate formula Mg₃Si₂O₅(OH)₄
Category: metamorphic
Identified: September 12, 2026
Method: Standard

AI Estimated Value

About $1–$10 for a small tumbled piece; $10–$50 for attractive polished or carved specimens.

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 such as peridotite undergo hydration and metamorphism, commonly during ocean-floor alteration or tectonic subduction; ages vary from Precambrian to modern. It commonly occurs in serpentinite bodies and ophiolites.

Uses & applications

Used as ornamental stone, carvings, beads, and occasionally architectural stone; softer varieties are popular inexpensive tumbling material. It is not generally suitable for high-wear jewelry.

Geological facts

Serpentine is often mistaken for jade, but is substantially softer and commonly has a waxier surface. Some specimens may contain chrysotile asbestos, so avoid cutting or generating dust unless tested.

Field identification & locations

Common localities include California, Italy, New Zealand, Canada, and the Ural Mountains. Field clues include greasy/waxy green appearance, low hardness, and association with dark ultramafic rocks; hardness and acid tests help separate it from calcite and quartz.