metamorphic
Polished greenstone / serpentine (probable)
Serpentinite, dominated by serpentine-group minerals such as antigorite, lizardite, or chrysotile
AI-generated identification · may be incorrectDark green to black, mottled and waxy-to-greasy luster with pale veining; typically Mohs hardness 2.5–4, nonmetallic, fine-grained and massive, with no obvious cleavage. The glossy surface appears polished or wet, and the specimen may be jade-like but cannot be confirmed as jade from an image.
Identified More metamorphic →
Explore Polished greenstone / serpentine (probable) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Dark green to black, mottled and waxy-to-greasy luster with pale veining; typically Mohs hardness 2.5–4, nonmetallic, fine-grained and massive, with no obvious cleavage. The glossy surface appears polished or wet, and the specimen may be jade-like but cannot be confirmed as jade from an image.
Formation & geological history
Forms when ultramafic mantle rocks are hydrated and altered during metamorphism, commonly in ancient oceanic crust and subduction zones; ages vary widely. Serpentinite is widespread in tectonic belts worldwide.
Uses & applications
Used as carving stone, ornamental material, cabochons, beads, and decorative objects; larger blocks may be used for countertops or facing, though fibrous chrysotile-bearing material requires caution.
Geological facts
Serpentine is often confused with nephrite jade, but is generally softer and less tough. Some varieties contain asbestos-form serpentine minerals, so avoid drilling, sanding, or creating dust.
Field identification & locations
Field clues include low hardness, green-black mottling, waxy appearance, and pale mesh-like veins; a steel knife may scratch it, whereas true jade is usually tougher. Common sources include California, New Zealand, Italy, Canada, and the Appalachians.
More like this
