metamorphic
Serpentinite (likely antigorite-rich)
Serpentine-group minerals, chiefly antigorite: Mg₃Si₂O₅(OH)₄, with possible magnetite, carbonate, and amphibole
AI-generated identification · may be incorrectDark green to black, mottled with pale green-white veins and patches; commonly waxy to greasy luster, massive texture, and poor visible cleavage. Hardness is typically 2.5–4 Mohs, with specific gravity around 2.5–2.6.
Identified More metamorphic →
Explore Serpentinite (likely antigorite-rich) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Dark green to black, mottled with pale green-white veins and patches; commonly waxy to greasy luster, massive texture, and poor visible cleavage. Hardness is typically 2.5–4 Mohs, with specific gravity around 2.5–2.6.
Formation & geological history
Forms when ultramafic mantle rocks such as peridotite undergo low-temperature hydrothermal alteration and hydration. It commonly develops in ophiolites and subduction-related mélanges, from Paleozoic to modern geological settings.
Uses & applications
Used as decorative and architectural stone, carvings, and lapidary material; historically used for ornamental objects and limited serpentine countertops. It is not generally valuable as a gemstone-quality specimen.
Geological facts
The pale veins may contain chrysotile, a fibrous serpentine mineral associated with asbestos; avoid cutting, grinding, or generating dust unless professionally tested and controlled.
Field identification & locations
Identify by its green-black mottling, greasy/waxy surface, softness, and association with white serpentine or carbonate veins; common in California, Italy, New Zealand, Canada, and ophiolite belts worldwide. Estimated value: $5–$30 for a small ordinary specimen, or $50–$150 if unusually attractive and polished.
More like this
