metamorphic

Tumbled serpentine

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

AI-generated identification · may be incorrect

Typically olive-green to blue-green with mottled dark veining, waxy to greasy luster, and opaque appearance; Mohs hardness 2.5–4, often with smooth tumbled surfaces and poor cleavage. The pictured specimen is consistent with serpentine, though exact identification requires testing.

Identified September 16, 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 undergo hydration and metamorphism, commonly in oceanic crust and subduction-zone mélanges. Serpentinization is generally Phanerozoic but occurs in rocks of many ages.

Uses & applications

Used as ornamental stone, carvings, beads, and decorative tile; some varieties have historical use as a jade substitute. Fibrous chrysotile varieties are asbestos-bearing and hazardous when dust is generated.

Geological facts

Its green color comes from iron and nickel-bearing alteration minerals; magnetite commonly forms during serpentinization. Serpentine is California’s state rock.

Field identification & locations

Look for a soft, waxy, mottled green stone that may scratch with a steel blade; it is commonly found in ultramafic terrains worldwide, including California, Italy, New Zealand, and Canada. Avoid sanding or breaking unknown specimens because some serpentine contains asbestos fibers.