metamorphic

Serpentinite

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

AI-generated identification · may be incorrect

Hardness: 2.5-4; Color: Greyish-green to dark green; Luster: Greasy, waxy, or silky; Crystal system: Monoclinic; Cleavage: Poor; Specific Gravity: 2.5-2.6

Hardness: 2
Color: Greyish-green to dark green
Luster: Greasy, waxy, or silky

Identified July 15, 2026More metamorphic →

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Physical properties

Hardness: 2.5-4; Color: Greyish-green to dark green; Luster: Greasy, waxy, or silky; Crystal system: Monoclinic; Cleavage: Poor; Specific Gravity: 2.5-2.6

Formation & geological history

Formed through the hydration and metamorphic transformation of ultramafic rocks (like peridotite) from the Earth's mantle at relatively low temperatures and high pressures.

Uses & applications

Used as a source of asbestos in the past, for decorative interior stonework, carvings, and as a railway ballast or road construction material.

Geological facts

It is the official state rock of California; the process of its formation (serpentinization) releases hydrogen and methane which may have supported early life on Earth.

Field identification & locations

Identify by its characteristic waxy 'serpent-like' green color and feel. Often found in ophiolite complexes where oceanic crust has been thrust onto continental crust.