Serpentine (Nephrite-like Serpentine)

Serpentinite (Hydrous magnesium iron phyllosilicate)

Rock Type: metamorphic

Serpentine (Nephrite-like Serpentine)

Physical Properties

Hardness: 3-6 Mohs scale; Color: olive green with white/gray inclusions; Luster: waxy to greasy; Crystal Structure: Monoclinic; Cleavage: poor; Specific Gravity: 2.5-2.8

Formation & Geological History

Formed through the hydrothermal alteration of ultramafic rocks (serpentinization) in the Earth's mantle or oceanic crust, typically at low temperatures and high pressures.

Uses & Applications

Used for ornamental carvings, decorative tiles, jewelry (often as a jade simulant), and historically for producing asbestos (though this variety is massive/non-asbestiform).

Geological Facts

Serpentinite is the state rock of California. It often looks like snakeskin, which is how it earned its name. It is chemically similar to Jade but is significantly softer.

Field Identification & Locations

Identify by its 'soapy' or greasy feel and olive green color. It can be scratched by a steel knife, unlike real Nephrite Jade. Commonly found along tectonic plate boundaries and ophiolite complexes.

Identified on: 4/26/2026

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