metamorphic

Tumbled serpentine

Serpentinite; chiefly antigorite, lizardite, and/or chrysotile Mg₃Si₂O₅(OH)₄

AI-generated identification · may be incorrect

A polished/tumbled dark green-gray specimen with mottled pale green and black areas, waxy to subvitreous luster, and no obvious crystal faces. Hardness is typically 2.5–4 Mohs; specific gravity about 2.5–2.6, with uneven to splintery fracture and commonly obscure cleavage.

Identified September 15, 2026More metamorphic →

Explore Tumbled serpentine in the encyclopedia →

Identify your own rocks.

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

App Store Google Play

Physical properties

Formation & geological history

Forms when ultramafic mantle rocks such as peridotite are hydrated during hydrothermal alteration, commonly in oceanic crust and subduction zones. Serpentinization is generally Mesozoic to modern, depending on the tectonic setting.

Uses & applications

Used as an ornamental stone, carvings, beads, countertops, and decorative tumbled material; historically used for tools and sculpture. Chrysotile-rich varieties may contain asbestos and should not be cut or powdered without proper controls.

Geological facts

The mottling resembles jade, but serpentine is softer and generally less dense. A photograph cannot distinguish serpentine confidently from nephrite, chlorite-rich rock, or other greenstones.

Field identification & locations

Common in California, Oregon, Vermont, Italy, New Zealand, Canada, and many ophiolite belts. Field clues include a smooth waxy feel, green-black veining, low hardness, and possible soapy texture; avoid scratch or asbestos testing on unknown material.