metamorphic

Serpentinite

Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4

AI-generated identification · may be incorrect

Hardness: 2.5-5 (Mohs), Color: shades of mottled green/black, Luster: waxy to greasy, Crystal structure: monoclinic (masses), Specific gravity: 2.5-2.6

Hardness: 2

Identified June 4, 2026More metamorphic →

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Physical properties

Hardness: 2.5-5 (Mohs), Color: shades of mottled green/black, Luster: waxy to greasy, Crystal structure: monoclinic (masses), Specific gravity: 2.5-2.6

Formation & geological history

Formed through the low-temperature hydrothermal metamorphic alteration of ultramafic rocks from the Earth's mantle, a process known as serpentinization, typically at tectonic plate boundaries.

Uses & applications

Used as decorative stone in interior architecture, source for magnesium and asbestos, and occasionally used in jewelry or as a base for carvings.

Geological facts

Serpentinite is the official state rock of California. When high-pressure metamorphic conditions occur, it can transform into rare jadeites.

Field identification & locations

Identify by its characteristic 'serpent-skin' mottled green appearance, waxy texture, and relative softness compared to quartz. Common in ophiolite complexes.