metamorphic
Serpentinite
Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4
Hardness: 3-6 Mohs. Color: Dark green to black, often mottled with yellowish-green patches. Luster: Greasy, waxy, or silky. Texture: Smooth and soapy to the touch. Cleavage: Poorly defined. Specific Gravity: 2.5-2.6.
- Hardness
- 3-6 Mohs
- Luster
- Greasy, waxy, or silky
Identified More metamorphic →
Explore Serpentinite in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 3-6 Mohs. Color: Dark green to black, often mottled with yellowish-green patches. Luster: Greasy, waxy, or silky. Texture: Smooth and soapy to the touch. Cleavage: Poorly defined. Specific Gravity: 2.5-2.6.
Formation & geological history
Formed through the hydration and metamorphic transformation of ultramafic rocks (peridotite) from the Earth's mantle, typically at tectonic plate boundaries (subduction zones).
Uses & applications
Used as ornamental stone, architectural trim, carving material, and historically as a source of asbestos. High-quality varieties are used in lapidary work.
Geological facts
Serpentinite is the official state rock of California. It often creates unique soil environments (serpentine soils) that are toxic to many plants but host rare, endemic species.
Field identification & locations
Identify by its characteristic 'serpent-like' green mottling, waxy luster, and smooth, soapy feel. Commonly found in ophiolite belts and mountain ranges like the Alps or the Pacific Coast Ranges.
More like this
