metamorphic

Greenstone pebble (likely serpentine-rich)

Serpentinite or chlorite-rich metamorphic rock; exact identification is uncertain from the photograph

AI-generated identification · may be incorrect

Small rounded gray-green pebble with pale, branching veins and a dull to slightly waxy surface. Hardness and mineral composition cannot be determined reliably from the image; serpentinite commonly has Mohs hardness of about 3–5 and no consistent cleavage.

Identified October 15, 2026More metamorphic →

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Physical properties

Formation & geological history

Likely formed when ultramafic rock was altered by water-rich fluids during metamorphism; such rocks occur in ancient and modern tectonic belts. The specimen’s age and precise origin are unknown.

Uses & applications

Small pebbles are mainly used for collecting, crafts, or decoration; serpentinite is also used as ornamental stone and, less commonly, as a source of industrial minerals.

Geological facts

Pale veins in greenstone may be calcite, quartz, or other minerals, so appearance alone cannot confirm serpentinite.

Field identification & locations

Look for a greenish color and waxy feel; a streak, hardness test, and acid test on a vein can help distinguish minerals. Green metamorphic rocks occur worldwide in mountain belts and ophiolites.