metamorphic
Tumbled green stone, likely serpentine
Serpentinite; chiefly serpentine-group minerals (antigorite, lizardite, chrysotile)
AI-generated identification · may be incorrectDark green to nearly black, waxy to subvitreous luster, fine-grained and opaque with pale veining; Mohs hardness about 2.5–4, generally massive rather than visibly crystalline. The rounded edges and glossy surface indicate tumbling or polishing.
Identified More metamorphic →
Explore Tumbled green stone, likely serpentine in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Dark green to nearly black, waxy to subvitreous luster, fine-grained and opaque with pale veining; Mohs hardness about 2.5–4, generally massive rather than visibly crystalline. The rounded edges and glossy surface indicate tumbling or polishing.
Formation & geological history
Forms when ultramafic mantle rocks such as peridotite undergo hydrothermal alteration and hydration, commonly along tectonic plate boundaries; ages vary widely from Precambrian to modern tectonic settings.
Uses & applications
Used as ornamental and carving stone, countertops, beads, cabochons, and decorative specimens; historically used for tools and architectural stone. Chrysotile-bearing material should not be cut or abraded because its fibers can be hazardous when airborne.
Geological facts
Serpentinite is the state rock of California and is associated with subduction zones and oceanic lithosphere. The image alone cannot distinguish it confidently from polished nephrite jade, chlorite-rich rock, or another dark-green stone.
Field identification & locations
Identify by its low hardness, greasy/waxy feel, green-black mottling, and possible white veins; a steel blade may scratch many serpentinites. Common localities include California, Italy, New Zealand, Canada, and ultramafic belts worldwide.
More like this
