metamorphic

Serpentinite (likely)

Serpentinite, dominated by serpentine-group minerals (antigorite, lizardite, chrysotile), commonly with magnetite and relic olivine/pyroxene

AI-generated identification · may be incorrect

Typically green to black, mottled, waxy to greasy luster; Mohs hardness 2.5–4, massive texture, poor visible cleavage, and specific gravity about 2.5–2.6. The specimen appears dark green-gray with pale altered patches and metallic-looking flecks, though a photo cannot confirm composition.

Identified August 11, 2026More metamorphic →

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At a glance

Common name: Serpentinite (likely)
Scientific name: Serpentinite, dominated by serpentine-group minerals (antigorite, lizardite, chrysotile), commonly with magnetite and relic olivine/pyroxene
Category: metamorphic
Identified: August 11, 2026
Method: Standard

AI Estimated Value

About $2–$20 for a common hand specimen; $25–$100+ for attractive polished or unusual collector material.

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 water alters ultramafic mantle rocks such as peridotite, usually along oceanic crust, subduction zones, and faults. Serpentinization ranges from Precambrian to recent geological ages.

Uses & applications

Used as decorative stone, carving material, aggregate, and historically as a building stone; attractive polished varieties are collected, but asbestos-bearing material should not be cut or powdered.

Geological facts

Often contains magnetite and may be weakly magnetic. Chrysotile-bearing serpentinite can release hazardous fibers when sawn, drilled, or abraded.

Field identification & locations

Check for a green waxy surface, low hardness, and possible magnetism; a streak, hardness test, and laboratory analysis distinguish it from chlorite schist, greenstone, or weathered basalt. Common in California, Italy, New Zealand, Canada, and ophiolite belts worldwide.