metamorphic

Serpentinite

Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)3Si2O5(OH)4

AI-generated identification · may be incorrect

Hardness: 3-6 (Mohs), Color: olive green to dark blackish-green, Luster: greasy, waxy, or silky, Crystal Structure: Monoclinic, Cleavage: Poor, Specific Gravity: 2.5-3.2, Texture: smooth to scaly.

Identified June 19, 2026More metamorphic →

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Physical properties

Hardness: 3-6 (Mohs), Color: olive green to dark blackish-green, Luster: greasy, waxy, or silky, Crystal Structure: Monoclinic, Cleavage: Poor, Specific Gravity: 2.5-3.2, Texture: smooth to scaly.

Formation & geological history

Formed at low temperatures through the hydration of ultramafic rocks (like peridotite) from the Earth's mantle, a process called serpentinization. Common in subduction zones and oceanic crust.

Uses & applications

Used as decorative building stone, in high-end carving and jewelry (sometimes as a jade stimulant), and historically as a source of asbestos and magnesium.

Geological facts

Serpentinite is the state rock of California. It can often contain trace amounts of asbestos and is known for producing poor, nutrient-deficient soils where only rare 'serpentine-endemic' plants can grow.

Field identification & locations

Identify by its characteristic 'snake-skin' green color and waxy feel. It is commonly found in mountain belts and along fault lines where deep crustal rocks have been pushed to the surface.