metamorphic

Likely serpentine or serpentinite

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

AI-generated identification · may be incorrect

Dark olive-green to gray, mottled and locally waxy or greasy luster; Mohs hardness about 2.5–4, low-to-moderate density, commonly massive with no obvious crystals or cleavage. The image is insufficient for a definitive identification;…

Identified September 16, 2026More metamorphic →

Explore Likely serpentine or serpentinite 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 magnesium-rich ultramafic rocks such as peridotite are hydrated during metamorphism, commonly in oceanic crust and subduction zones. Ages range from modern alteration to Precambrian, depending on the host rock.

Uses & applications

Used decoratively as ornamental stone, carvings, and sometimes countertops; historically, asbestos-bearing varieties were used industrially, though hazardous fibers should not be disturbed.

Geological facts

Commonly associated with chromite, magnetite, talc, and nephrite. Avoid cutting, grinding, or heating unknown specimens because chrysotile asbestos may be present.

Field identification & locations

Look for a smooth, greasy feel, olive-green mottling, low hardness, and a pale streak; a steel nail may scratch it. Common localities include California, Italy, New Zealand, Canada, and serpentinite belts worldwide.