metamorphic

Likely serpentinite (serpentine-rich rock)

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

AI-generated identification · may be incorrect

Dark green-gray, mottled, dull to waxy luster, massive and fine-grained; typically Mohs 2.5–4, with no obvious cleavage. The image is insufficient for confident identification; similar appearance occurs in altered ultramafic rocks.

Identified September 3, 2026More metamorphic →

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At a glance

Common name: Likely serpentinite (serpentine-rich rock)
Scientific name: Serpentinite; chiefly serpentine-group minerals, Mg₃Si₂O₅(OH)₄, with possible magnetite, olivine, and pyroxene
Category: metamorphic
Identified: September 3, 2026
Method: Standard

AI Estimated Value

About $2–$15 for a common hand specimen; $20–$100+ for attractive polished or unusual 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 mantle-derived peridotite is hydrated and metamorphosed by circulating water, commonly in oceanic crust and subduction zones; ages range from Precambrian to modern tectonic settings.

Uses & applications

Used as decorative stone, carvings, countertops, and occasionally architectural material; historically used for ornaments and heat-resistant objects. Usually modest collector value.

Geological facts

Serpentinite may contain fibrous chrysotile, a naturally occurring asbestos mineral, so avoid cutting, drilling, or generating dust without proper controls.

Field identification & locations

Check for a green, greasy/waxy surface, relatively low hardness, and possible magnetism from magnetite; a streak, hardness, acid, and density test would improve identification. Common in California, Italy, New Zealand, Canada, and tectonic mountain belts.