metamorphic

Polished serpentine-rich rock (likely serpentinite)

Serpentinite; chiefly serpentine-group minerals, Mg₃Si₂O₅(OH)₄, with possible magnetite, chlorite, and carbonate

AI-generated identification · may be incorrect

Typically green to yellow-green, mottled, waxy to greasy luster, and fine-grained with no visible crystal faces; Mohs hardness about 2.5–4, commonly with irregular fracture and specific gravity around 2.5–2.6. The reddish-brown patches may be iron oxides or associated rock inclusions.

Identified August 20, 2026More metamorphic →

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At a glance

Common name: Polished serpentine-rich rock (likely serpentinite)
Scientific name: Serpentinite; chiefly serpentine-group minerals, Mg₃Si₂O₅(OH)₄, with possible magnetite, chlorite, and carbonate
Category: metamorphic
Identified: August 20, 2026
Method: Standard

AI Estimated Value

About $5–$25 for a small polished common piece; $30–$100+ for attractive, large, or jade-like 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

Forms when ultramafic mantle rocks such as peridotite hydrate during hydrothermal alteration, commonly along faults and oceanic crust; ages vary from ancient Precambrian occurrences to modern tectonic zones.

Uses & applications

Used as a decorative and carving stone, tumbled-stone material, countertops, and historically as a source of asbestos-bearing minerals; avoid cutting or abrading unknown specimens because some serpentinite contains chrysotile asbestos.

Geological facts

Its distinctive green color results from hydration and alteration of magnesium-rich minerals. It is often confused with jade, but is generally softer and less tough.

Field identification & locations

Common in convergent-margin and ophiolite belts, including California, Italy, New Zealand, and Canada; field clues are green mottling, waxy feel, low hardness, and occasional magnetism. A definitive identification requires microscopy or X-ray analysis.