metamorphic
Serpentinite
Serpentinite (composed primarily of Serpentine group minerals, Mg3Si2O5(OH)4)
Hardness: 3-6 (variable based on mineral composition); Color: Pale to dark green, often mottled with black spots; Luster: Greasy, waxy, or silky; Crystal structure: Monoclinic; Cleavage: Poor/absent in rock form; Specific gravity: 2.2-2.9
- Hardness
- 3-6 (variable based on mineral composition)
- Color
- Pale to dark green, often mottled with black spots
- Luster
- Greasy, waxy, or silky
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 3-6 (variable based on mineral composition); Color: Pale to dark green, often mottled with black spots; Luster: Greasy, waxy, or silky; Crystal structure: Monoclinic; Cleavage: Poor/absent in rock form; Specific gravity: 2.2-2.9
Formation & geological history
Formed through the hydrothermal metamorphism (serpentinization) of mafic and ultramafic igneous rocks like peridotite, typically at tectonic plate boundaries or mid-ocean ridges.
Uses & applications
Used as decorative stone in architecture (faux-marble), carvings, and historically as a source of asbestos. High-quality specimens are used for jewelry or lapidary work.
Geological facts
Serpentinite is the official state rock of California. It often creates unique soil conditions that lead to specialized plant biodiversity called serpentine barrens.
Field identification & locations
Identify by its characteristic 'serpent-like' green mottled appearance and slick, waxy feel. Commonly found in ophiolite complexes and subduction zones in places like California, the Alps, and Greece.
More like this
