metamorphic
Tumbled serpentine
Serpentinite; chiefly antigorite, lizardite, and/or chrysotile-group minerals
AI-generated identification · may be incorrectTypically dark green to gray-green, mottled, waxy to slightly greasy luster, fine-grained and massive; Mohs hardness about 2.5–4, with poor or indistinct cleavage and specific gravity around 2.5–2.6. The rounded shape and smooth surface indicate mechanical tumbling or polishing.
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Physical properties
Typically dark green to gray-green, mottled, waxy to slightly greasy luster, fine-grained and massive; Mohs hardness about 2.5–4, with poor or indistinct cleavage and specific gravity around 2.5–2.6. The rounded shape and smooth surface indicate mechanical tumbling or polishing.
Formation & geological history
Forms when ultramafic mantle rocks such as peridotite are hydrated during metamorphism, commonly along seafloor spreading zones and subduction-related faults. Serpentinization ranges from Precambrian to modern geological settings.
Uses & applications
Used as a decorative stone, carving material, polished pebble, and occasionally for countertops; historically used for ornamental objects. Fibrous chrysotile varieties have asbestos hazards and should not be cut, drilled, or powdered.
Geological facts
Often resembles jade but is generally softer and less durable; veining may consist of magnetite, carbonate, or other alteration minerals.
Field identification & locations
Identify by its green mottling, relatively low hardness, waxy feel, and frequent dark veins; common in California, the Alps, New Zealand, Canada, and ultramafic terranes worldwide.
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