metamorphic

Serpentine (likely serpentinized ultramafic rock)

Serpentinite; chiefly antigorite, lizardite, or chrysotile Mg₃Si₂O₅(OH)₄, often with magnetite and relict olivine/pyroxene

AI-generated identification · may be incorrect

Typically mottled gray-green to black, waxy or greasy luster, fine-grained and massive; Mohs hardness 2.5–4, no prominent cleavage, density about 2.5–2.6. The specimen appears green-gray and brecciated, but a photo cannot confirm the identification.

Identified September 18, 2026More metamorphic →

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At a glance

Common name: Serpentine (likely serpentinized ultramafic rock)
Scientific name: Serpentinite; chiefly antigorite, lizardite, or chrysotile Mg₃Si₂O₅(OH)₄, often with magnetite and relict olivine/pyroxene
Category: metamorphic
Identified: September 18, 2026
Method: Standard

AI Estimated Value

About $5–$30 for a small common specimen; $30–$150+ for attractive polished or display-quality 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 mantle-derived peridotite is hydrated and altered by low-temperature metamorphism, commonly along faults and oceanic crust; ages range from Precambrian to modern tectonic settings.

Uses & applications

Used as decorative stone, carvings, countertops, and historically as a source of asbestos-bearing material; attractive pieces are collected as lapidary specimens.

Geological facts

Often has a distinctive mottled or “snakeskin” appearance and may contain magnetite, making some pieces weakly magnetic. Fibrous chrysotile varieties require care because disturbed asbestos fibers are hazardous.

Field identification & locations

Look for green-black mottling, waxy texture, softness, and association with ultramafic rocks; common in California, Italy, New Zealand, Canada, and mountain belts worldwide. Avoid cutting or sanding unknown pieces.