metamorphic

Polished serpentine (likely)

Serpentine-group minerals, chiefly antigorite/lizardite; commonly associated with magnetite and chromite

AI-generated identification · may be incorrect

Hardness about 2.5–4 Mohs; mottled yellow-green, olive, black, and brown with a waxy to vitreous luster. Typically massive rather than visibly crystalline, with irregular fracture and moderate-to-high specific gravity (about 2.5–2.7).

Identified September 17, 2026More metamorphic →

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Physical properties

Formation & geological history

Forms when ultramafic mantle rocks such as peridotite are hydrated during hydrothermal alteration or tectonic uplift, commonly in ophiolites; ages range from Precambrian to modern tectonic settings.

Uses & applications

Used as ornamental stone, cabochons, carvings, and occasionally architectural material; attractive translucent green pieces have modest lapidary value.

Geological facts

The image appears to show a small polished or tumbled fragment, but exact identification requires hardness, streak, and chemical testing. Some serpentine varieties may contain asbestos-form minerals, so avoid cutting or generating dust.

Field identification & locations

Common in California, Italy, New Zealand, Canada, Russia, and Japan; identify by green mottling, waxy polish, low hardness, and lack of strong cleavage. The specimen could also be a related greenstone or altered rock.