metamorphic

Greenstone / serpentinite (probable)

Serpentinite, chiefly serpentine-group minerals (Mg₃Si₂O₅(OH)₄), possibly chlorite or epidote

AI-generated identification · may be incorrect

Small rounded green-gray specimen with mottled coloration and a dull to slightly waxy luster; likely Mohs hardness 2.5–4, with no obvious crystal faces or cleavage. Exact identification requires hardness, streak, density, and microscopy tests.

Identified September 7, 2026More metamorphic →

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Physical properties

Formation & geological history

Typically forms when magnesium-rich ultramafic rocks, especially peridotite, are hydrated and metamorphosed during tectonic activity; occurrences range from Precambrian to modern active fault zones.

Uses & applications

Used decoratively as ornamental stone, carvings, and occasionally dimension stone; attractive pieces are collected, though this small specimen has limited commercial value.

Geological facts

Serpentinite commonly displays mottled green, black, and yellow-green patterns and may contain magnetite, giving some pieces weak magnetism. The image alone cannot distinguish it confidently from greenstone, chlorite schist, or weathered basalt.

Field identification & locations

Look for a soft, waxy-feeling green surface, fine mottling, and a pale streak; it may scratch with a steel knife. Common sources include ophiolite belts, California, Vermont, Italy, New Zealand, and the Alps.