metamorphic

Tumbled serpentine with magnetite/chromite veining

Serpentinite; chiefly serpentine-group minerals, Mg₃Si₂O₅(OH)₄, with opaque magnetite or chromite

AI-generated identification · may be incorrect

Typically Mohs 2.5–4, waxy to greasy luster, pale green-yellow to brown with black veins or patches, and fine-grained massive structure; no visible cleavage. The wet, polished appearance and black mineral inclusions fit serpentine, though image-only identification is provisional.

Identified September 15, 2026More metamorphic →

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At a glance

Common name: Tumbled serpentine with magnetite/chromite veining
Scientific name: Serpentinite; chiefly serpentine-group minerals, Mg₃Si₂O₅(OH)₄, with opaque magnetite or chromite
Category: metamorphic
Identified: September 15, 2026
Method: Standard

AI Estimated Value

About $3–$20 for a small tumbled specimen; $20–$75 for attractive polished or well-provenanced pieces.

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 are hydrated during hydrothermal alteration, commonly in ophiolites and subduction zones. Ages vary widely, from ancient Precambrian bodies to modern alteration zones.

Uses & applications

Used as ornamental stone, beads, carvings, and occasionally architectural stone; softer pieces are popular tumbled specimens. Avoid prolonged exposure to dust from cutting, particularly if asbestos-form serpentine minerals are present.

Geological facts

The black material may be magnetite or chromite; magnetite can be weakly magnetic. Serpentinite is often mottled, slick-looking, and associated with chromite deposits.

Field identification & locations

Look for low hardness, waxy luster, green-yellow coloration, and black veining; a steel nail may scratch it, unlike jade. Common in California, Italy, New Zealand, Canada, and ophiolite belts worldwide.