Serpentine

Physical Properties

Hardness: 3-6 (Mohs scale), Color: diverse shades of green to yellow-green, Luster: waxy, greasy or silky, Crystal structure: Monoclinic, Cleavage: poor to perfect depending on variety, Specific Gravity: 2.5-2.6

Formation & Geological History

Formed through serpentinization, an exothermic chemical reaction where water enters hydration of ultramafic rock from the Earth's mantle at low temperatures. It is often found along tectonic plate boundaries and in ophiolites.

Uses & Applications

Used as a decorative architectural stone (Verde Antique), for carving sculptures, as a source for magnesium, and historically as an asbestos source (chrysotile), though primarily now as a gemstone or collector specimen.

Geological Facts

The name comes from 'serpent' due to its green scaly appearance. It is the official state rock of California. When high-pressure water hits mantle rocks, it expands the volume, often causing seismic activity.

Field Identification & Locations

Identify in the field by its characteristic waxy 'soapy' feel, distinctive green color, and often mottled or veined appearance. Common near fault zones and oceanic crust exposure.

Identified on: 4/19/2026

Mode: Standard