metamorphic

Likely dark green-black tumbled stone (possibly serpentine)

Unconfirmed; appearance is consistent with serpentine, a group of hydrated magnesium silicate minerals

AI-generated identification · may be incorrect

Small, rounded, opaque dark green-black piece with a smooth, slightly glossy surface. If serpentine, hardness is about 2.5–5 Mohs and its crystal structure is typically fine-grained; the image is insufficient to establish composition or cleavage.

Identified September 26, 2026More metamorphic →

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At a glance

Common name: Likely dark green-black tumbled stone (possibly serpentine)
Scientific name: Unconfirmed; appearance is consistent with serpentine, a group of hydrated magnesium silicate minerals
Category: metamorphic
Identified: September 26, 2026
Method: Standard

AI Estimated Value

About $1–$10 for a small common tumbled stone; identification and quality could change this estimate.

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 water alters magnesium-rich rocks, commonly in ancient oceanic crust and mantle-derived rocks; its age depends on the host geology.

Uses & applications

Often polished for ornaments, beads, and carvings; serpentine is also used as a decorative stone.

Geological facts

The specimen is too small and visually ambiguous for a reliable identification; similar dark tumbled pieces may be other rocks or minerals.

Field identification & locations

Check for a waxy feel, green tones, and relatively easy scratching to assess serpentine; confirm with hardness and mineral tests. Serpentine occurs in ultramafic-rock belts worldwide.