metamorphic
Serpentine
Serpentinite (composed mainly of Group Minerals Antigorite, Chrysotile, and Lizardite; Mg3Si2O5(OH)4)
Hardness: 3-6 (Mohs), Color: olive green, dark green, or blackish green with mottled patches, Luster: waxy, greasy or silky, Crystal structure: Monoclinic, Cleavage: poor, Specific gravity: 2.5-2.6
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 3-6 (Mohs), Color: olive green, dark green, or blackish green with mottled patches, Luster: waxy, greasy or silky, Crystal structure: Monoclinic, Cleavage: poor, Specific gravity: 2.5-2.6
Formation & geological history
Formed through serpentinization, a metamorphic process where low-silica ultramafic rocks from the Earth's mantle are hydrated and chemically transformed at low temperatures near tectonic plate boundaries.
Uses & applications
Used as decorative architectural stone, in jewelry (often as a jade substitute), and historically as a source of asbestos. High-quality varieties like Bowenite are prized for carvings.
Geological facts
It is the official state rock of California. The name 'serpentine' comes from the mottled green appearance resembling the skin of a serpent. It often contains magnetite, which can make some specimens slightly magnetic.
Field identification & locations
Identify in the field by its characteristic 'greasy' feel, green mottled color, and relative softness (can often be scratched by a copper penny or steel blade). Commonly found in ophiolite belts like those in the Coast Ranges of California, the Alps, and the Himalayas.
More like this
