metamorphic

Polished serpentine-rich metamorphic rock

Serpentinite, chiefly serpentine-group minerals (Mg₃Si₂O₅(OH)₄), with possible magnetite, chlorite, or talc

AI-generated identification · may be incorrect

Dark olive-green to black, mottled and waxy to subvitreous luster with fibrous/foliated bands; Mohs hardness about 2.5–4, commonly dense and tough but with uneven fracture. The polished surface highlights slick green, yellow, and brown mineral veining.

Identified September 10, 2026More metamorphic →

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At a glance

Common name: Polished serpentine-rich metamorphic rock
Scientific name: Serpentinite, chiefly serpentine-group minerals (Mg₃Si₂O₅(OH)₄), with possible magnetite, chlorite, or talc
Category: metamorphic
Identified: September 10, 2026
Method: Standard

AI Estimated Value

Approximately $10–$60 for a hand-sized polished specimen; $75–$300+ for unusually patterned, large, or finely finished 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 and altered during tectonic processes, especially at oceanic crust and subduction zones. Most examples represent Paleozoic to Mesozoic or younger tectonic belts, though age depends on locality.

Uses & applications

Used as decorative stone, ornamental carvings, countertops, and lapidary material; attractive pieces are collected as serpentine or “new jade.” Avoid dust from cutting because some serpentinite may contain chrysotile asbestos.

Geological facts

Its green color results from hydration of olivine- and pyroxene-rich rocks. Magnetite produced during alteration can make some specimens weakly magnetic.

Field identification & locations

Identify it by its green-black mottling, greasy/waxy polish, low hardness, and association with sheared ultramafic rock; common sources include California, Italy, New Zealand, Canada, and the Ural Mountains.