metamorphic
Serpentinite
Serpentinite (composed primarily of Serpentine group minerals: (Mg,Fe)3Si2O5(OH)4)
Hardness: 2.5 to 5 on Mohs scale; Color: typically shades of green (light to very dark), sometimes grayish or brownish; Luster: waxy, greasy, or silky; Crystal Structure: Monoclinic; Cleavage: poor/irregular; Specific Gravity: 2.5–2.6.
- Hardness
- 2
- Luster
- waxy, greasy, 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: 2.5 to 5 on Mohs scale; Color: typically shades of green (light to very dark), sometimes grayish or brownish; Luster: waxy, greasy, or silky; Crystal Structure: Monoclinic; Cleavage: poor/irregular; 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, typically at tectonic plate boundaries or subduction zones.
Uses & applications
Used as a decorative building stone (countertops, tiles), as a source of magnesium, historically for asbestos, and in some jewelry as 'New Jade'.
Geological facts
Serpentinite is the official state rock of California. It often creates unique soil conditions that support rare, endemic plant species that can tolerate high heavy metal concentrations.
Field identification & locations
Identify by its characteristic green 'snakeskin' appearance and waxy feel. It is common in ophiolite complexes and mountain ranges like the Appalachians or the California Coast Ranges.
More like this
