metamorphic

Weathered green-gray stone, likely serpentinite or chlorite-rich metamorphic rock

Probable serpentinite (antigorite–lizardite), possibly chlorite schist or altered basalt

AI-generated identification · may be incorrect

Fine-grained, dull to faintly waxy luster, gray-green color, rounded by weathering; typical hardness is about 2.5–4 Mohs for serpentinite, with no visible cleavage or crystals. Exact identification requires testing for hardness, streak, density, and reaction to acid.

Identified August 10, 2026More metamorphic →

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At a glance

Common name: Weathered green-gray stone, likely serpentinite or chlorite-rich metamorphic rock
Scientific name: Probable serpentinite (antigorite–lizardite), possibly chlorite schist or altered basalt
Category: metamorphic
Identified: August 10, 2026
Method: Standard

AI Estimated Value

About $1–$10 for a common hand specimen; $10–$50 if unusually attractive, polished, or locality-documented.

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

Likely formed when ultramafic mantle rock was hydrated during metamorphism, commonly in oceanic crust and subduction zones; ages vary widely from Paleozoic to recent tectonic exposures. The rounded shape indicates stream or surface weathering.

Uses & applications

Unusual pieces may be used as teaching specimens, landscaping stone, or low-grade carving material; attractive polished serpentinite is sometimes used decoratively. This small rough specimen has minimal commercial value.

Geological facts

Serpentinite commonly contains serpentine minerals and may include magnetite, chromite, or asbestos-form minerals; avoid cutting, sanding, or generating dust until identified. Its green color and smooth, soapy feel are characteristic.

Field identification & locations

Common in ophiolites and tectonic belts, including California, Italy, New Zealand, and the Appalachians. A steel nail may scratch it, while it generally will not scratch glass; a close photo cannot distinguish it confidently from altered basalt or chlorite-rich rock.