Serpentinite (often called Jade or Nephrite substitute)

Physical Properties

Hardness: 3-6 (depending on mineral mix); Color: typically dark green, mottled, or yellowish-green; Luster: waxy to greasy; Crystal Structure: Monoclinic; Cleavage: poor/none (massive form); Specific Gravity: 2.5-3.3.

Formation & Geological History

Formed by the low-grade metamorphism (serpentinization) of ultramafic rock (like peridotite) from the Earth's mantle, typically at mid-ocean ridges or subduction zones as seawater reacts with hot rock.

Uses & Applications

Used primarily as decorative stone, in jewelry (beads, cabochons), carvings, and historically as a construction material for veneers or floor tiles.

Geological Facts

Serpentinite is the official state rock of California. It often contains veins of chrysotile, which is the most common form of asbestos, though polished specimens are generally considered safe to handle.

Field Identification & Locations

Identify by its 'serpentine' or snakeskin-like mottled appearance, waxy texture, and relative softness compared to real Jadeite. Commonly found in mountain ranges that were once ancient sea floors, such as those in New Zealand, the Alps, and the U.S. West Coast.

Identified on: 5/16/2026

Mode: Standard