metamorphic
Tumbled serpentinite
Serpentinite, composed chiefly of serpentine-group minerals (lizardite, antigorite, chrysotile), commonly with magnetite and chlorite
AI-generated identification · may be incorrectTypically dark green to black with pale green veining, waxy to greasy luster, and mottled or streaked texture; Mohs hardness 2.5–4, generally massive rather than visibly crystalline, with poor cleavage and specific gravity about 2.5–2.6.
Identified More metamorphic →
Explore Tumbled serpentinite in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Typically dark green to black with pale green veining, waxy to greasy luster, and mottled or streaked texture; Mohs hardness 2.5–4, generally massive rather than visibly crystalline, with poor cleavage and specific gravity about 2.5–2.6.
Formation & geological history
Forms when ultramafic mantle rocks such as peridotite are hydrothermally altered by water, commonly along oceanic crust and subduction zones; specimens may range from ancient Precambrian to modern tectonic settings.
Uses & applications
Used as decorative stone, carvings, tumbled stones, countertops, and historically for ornamental objects; fibrous chrysotile-bearing material should not be cut or powdered because of asbestos risk.
Geological facts
Its green color reflects serpentine minerals and iron-bearing alteration products; magnetite commonly makes serpentinite weakly magnetic. The pictured piece appears polished or naturally smoothed by tumbling.
Field identification & locations
Identify by its green-black color, waxy feel, soft-to-moderate hardness, and often slick or fibrous-looking veins; common localities include California, the Appalachians, New Zealand, Italy, and the Canadian Shield.
More like this
