metamorphic

Likely serpentinite or serpentinized ultramafic rock

Serpentinite; chiefly serpentine-group minerals (antigorite, lizardite, chrysotile), commonly with magnetite and relict olivine/pyroxene

AI-generated identification · may be incorrect

Dark green-gray, mottled and massive with a dull to waxy luster; Mohs hardness about 2.5–4, typically low cleavage, fine-grained to subtly fibrous, and relatively dense (specific gravity about 2.5–2.7). The photograph is somewhat blurry, so exact identification is uncertain.

Identified August 21, 2026More metamorphic →

Explore Likely serpentinite or serpentinized ultramafic rock in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

At a glance

Common name: Likely serpentinite or serpentinized ultramafic rock
Scientific name: Serpentinite; chiefly serpentine-group minerals (antigorite, lizardite, chrysotile), commonly with magnetite and relict olivine/pyroxene
Category: metamorphic
Identified: August 21, 2026
Method: Standard

AI Estimated Value

About $5–$30 for a common rough hand specimen; $30–$150 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 mantle-derived peridotite is hydrated and metamorphosed by water, commonly along oceanic crust and subduction-zone faults. Serpentinization ranges from ancient Precambrian to modern geological activity.

Uses & applications

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

Geological facts

Serpentinite may show slick, waxy surfaces and can contain magnetite, making it weakly magnetic. Chrysotile-bearing varieties should not be cut, drilled, or abraded because inhaled fibers are hazardous.

Field identification & locations

Likely if the specimen is greenish, unusually smooth or waxy, dense, and weakly magnetic; a streak, hardness, magnet test, and fresh surface would help confirm it. Common locations include California, Italy, New Zealand, Canada, and the Appalachian and Alpine belts.