Serpentine

Physical Properties

Hardness: 3-6 (Mohs scale); Color: Green, yellowish-green, or brownish-black; Luster: Waxy, greasy, or silky; Crystal structure: Monoclinic; Cleavage: Poor to perfect depending on variety; Specific gravity: 2.2-2.9

Formation & Geological History

Formed through serpentinization, a process where ultramafic rocks (like peridotite) are altered by hydrothermal fluids at low temperatures and high pressures, often at tectonic plate boundaries.

Uses & Applications

Used for ornamental carvings, architectural stone (Vermont Marble), jewelry (often as a substitute for jade), and historically as a source of asbestos in some varieties.

Geological Facts

Serpentine is the state rock of California. It is named for its resemblance to the skin of a serpent, and it can often feel soapy or slippery to the touch.

Field Identification & Locations

Identify by its characteristic green color, waxy feel, and variable hardness. It is commonly found in ophiolite complexes and subduction zones. In the field, look for 'slickensides' or polished surfaces caused by tectonic movement.

Identified on: 4/19/2026

Mode: Standard