Serpentine

Physical Properties

Hardness: 3-6 Mohs scale; Color: Dark green, olive-green, mottled; Luster: Waxy, greasy, or silky; Crystal structure: Monoclinic; Cleavage: Poor; Specific Gravity: 2.5–2.6.

Formation & Geological History

Formed by the hydration of ultramafic rocks (peridotite) from the Earth's mantle through a process called serpentinization. This typically occurs at tectonic plate boundaries and subduction zones where seawater meets mantle rocks.

Uses & Applications

Used as an ornamental stone in architecture, as a source for magnesium and asbestos (historically), in jewelry as a substitute for jade, and for spiritual/collecting purposes.

Geological Facts

Serpentine is the official state rock of California. It is so named because its green color and scaly appearance resemble the skin of a serpent. Some varieties are called 'New Jade' in the gemstone market.

Field Identification & Locations

Identify by its characteristic 'greasy' touch, green mottled coloration, and relative softness compared to real jade. Often found in mountain ranges and near fault lines where deep crustal rocks have been pushed to the surface.

Identified on: 4/27/2026

Mode: Standard