metamorphic
Serpentinite
Serpentinite (Hydrated magnesium iron silicate)
Hardness: 2.5 to 5.5 on the Mohs scale depending on specific mineral make-up, Color: Shades of green, yellowish, brownish, or grayish, Luster: Greasy, waxy, or silky, Crystal structure: Monoclinic (serpentine group minerals), Cleavage: Poor to distinct, Specific Gravity: 2.4 to 2.6.
- Hardness
- 2
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: 2.5 to 5.5 on the Mohs scale depending on specific mineral make-up, Color: Shades of green, yellowish, brownish, or grayish, Luster: Greasy, waxy, or silky, Crystal structure: Monoclinic (serpentine group minerals), Cleavage: Poor to distinct, Specific Gravity: 2.4 to 2.6.
Formation & geological history
Formed through serpentinization, a low-temperature metamorphic process involving the hydrothermal alteration of ultramafic rocks (such as dunite or peridotite) from the Earth's mantle, typically occurring at ocean ridges or subduction zones.
Uses & applications
Used as an ornamental stone, for carving, architecture, interior decoration, and as a source of asbestos historically, though less common today due to health regulations.
Geological facts
Serpentinite is the state rock of California and often hosts interesting mineral associations like chrysotile, talc, and sometimes precious gemstones like jade or demantoid garnet.
Field identification & locations
Identify in the field by its characteristic mottled green coloration, smooth or waxy feel, and softness compared to standard igneous rocks. Common in mountain belts where ancient oceanic crust has been emplaced onto continents.
More like this
