metamorphic

Tumbled serpentine or serpentinite

Serpentine-group minerals, chiefly antigorite, lizardite, or chrysotile; approximate formula Mg₃Si₂O₅(OH)₄

AI-generated identification · may be incorrect

Light olive-gray, waxy to dull luster with pale veining and polished/tumbled surfaces; hardness about 2.5–4 Mohs, typically massive rather than visibly crystalline, with uneven fracture and specific gravity around 2.5–2.6.

Identified September 7, 2026More metamorphic →

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At a glance

Common name: Tumbled serpentine or serpentinite
Scientific name: Serpentine-group minerals, chiefly antigorite, lizardite, or chrysotile; approximate formula Mg₃Si₂O₅(OH)₄
Category: metamorphic
Identified: September 7, 2026
Method: Standard

AI Estimated Value

$3–$20 for a small common tumbled stone; $20–$75 for attractive, well-polished material or distinctive patterns.

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 ultramafic mantle rocks such as peridotite hydrate during hydrothermal alteration, commonly in ancient and active plate-boundary zones; the pictured piece is human-tumbled. Exact age cannot be determined visually.

Uses & applications

Used as ornamental stone, carvings, cabochons, countertops, and low-cost lapidary material; fibrous chrysotile varieties are hazardous if they release asbestos fibers and should not be cut or abraded.

Geological facts

Its green color comes from iron and nickel-bearing serpentine minerals, while pale mesh-like lines may reflect veining or the original rock texture. Serpentinite is California’s state rock.

Field identification & locations

Identify by its green-gray color, very low hardness, waxy feel, and commonly mottled or veined texture; common sources include California, Italy, New Zealand, Canada, and Zimbabwe. A scratch test and specific mineral analysis are needed for certainty.