Serpentine

Physical Properties

Hardness: 3-6 Mohs. Color: Greenish-black, olive green, or yellow-green. Luster: Greasy, waxy, or silky. Crystal structure: Monoclinic. Cleavage: Poor. Specific Gravity: 2.2-2.9.

Formation & Geological History

Formed through serpentinization, which occurs when ultramafic rocks (like peridotite) from the Earth's mantle are chemically altered by water at low temperatures/high pressures. Common in oceanic crust subduction zones.

Uses & Applications

Used as an architectural stone, for decorative carvings, and historically as a source of asbestos. High-quality translucent varieties are used in jewelry as 'New Jade'.

Geological Facts

Serpentine is the state rock of California. It is often called 'Snake Rock' due to its mottled green appearance resembling snake skin. It can host rare ecosystems because of its unique mineral chemistry.

Field Identification & Locations

Identify by its waxy luster, smooth/soapy feel, and characteristic forest-green color. Often associated with magnetite. Found in California, Vermont, Italy, and Cornwall.

Identified on: 4/25/2026

Mode: Standard