metamorphic
Serpentinite (serpentinized ultramafic rock)
Serpentine-group minerals, chiefly lizardite and antigorite; commonly derived from peridotite
AI-generated identification · may be incorrectPale green to gray, mottled and locally waxy with fibrous/veined textures; Mohs hardness about 2.5–4, commonly nongranular, with a dull to waxy luster. Specific gravity typically 2.5–2.6; cleavage is poor, though chrysotile veins may be fibrous.
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Physical properties
Pale green to gray, mottled and locally waxy with fibrous/veined textures; Mohs hardness about 2.5–4, commonly nongranular, with a dull to waxy luster. Specific gravity typically 2.5–2.6; cleavage is poor, though chrysotile veins may be fibrous.
Formation & geological history
Forms when mantle-derived peridotite is hydrated and altered by water during ocean-floor metamorphism or tectonic uplift. The image is consistent with serpentinite, but age cannot be determined visually.
Uses & applications
Used as decorative and architectural stone, carvings, and aggregate; attractive pieces are collected. Avoid cutting or grinding unknown serpentinite because some varieties contain asbestos-form chrysotile.
Geological facts
The green color comes from serpentine minerals and minor magnetite, chlorite, or carbonate. It often occurs in ophiolite belts and along major faults.
Field identification & locations
The mottled green-gray, slick-looking mass strongly supports serpentinite, though identification is provisional from one photograph. Around 38.3°N, 48.8°E, tectonically active ultramafic/ophiolitic rocks make this plausible; confirm with a streak, hardness test, and ideally thin-section or XRD analysis.
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