mineral

Tumbled green stone, possibly serpentine or prehnite

Provisional identification: serpentine-group mineral, commonly antigorite; alternatively prehnite or green calcite

AI-generated identification · may be incorrect

Pale green, opaque to translucent, rounded and polished with a dull-to-waxy luster; likely Mohs 2.5–6 depending on species. The blurred image does not resolve cleavage, crystal structure, or specific gravity.

Identified September 7, 2026More mineral →

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At a glance

Common name: Tumbled green stone, possibly serpentine or prehnite
Scientific name: Provisional identification: serpentine-group mineral, commonly antigorite; alternatively prehnite or green calcite
Category: mineral
Identified: September 7, 2026
Method: Standard

AI Estimated Value

Approximately $2–$15 for a common tumbled stone; $20–$100+ if confirmed as attractive gem-quality prehnite or a scarce variety.

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 undergo hydration and alteration, commonly in convergent-plate settings; prehnite forms in low-temperature hydrothermal veins and cavities. Geological ages vary widely.

Uses & applications

Tumbled pieces are sold as decorative specimens, craft stones, and metaphysical items; serpentine may also be carved or used decoratively, while prehnite is occasionally used in jewelry.

Geological facts

Identification is uncertain because the specimen is small, rounded, and out of focus; color alone cannot reliably distinguish green minerals.

Field identification & locations

Check streak, hardness, translucency, specific gravity, and reaction to dilute acid; serpentine is typically waxy and softer, whereas prehnite is harder and often translucent with a pearly sheen. Common sources include California, Italy, New Zealand, South Africa, and Australia.