metamorphic

Tumbled greenstone/chlorite-rich pebble

Likely chlorite-rich greenschist or altered basalt; exact identification requires testing

AI-generated identification · may be incorrect

Dark olive-green, opaque, smooth and glossy from tumbling/polishing, with fine-grained texture and no visible crystals. Likely Mohs hardness 5–6; cleavage is not apparent and specific gravity is approximately 2.8–3.1.

Identified August 10, 2026More metamorphic →

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Physical properties

Formation & geological history

Probably formed by low-grade metamorphism or hydrothermal alteration of basalt, converting mafic minerals to chlorite, epidote, and amphibole; commonly Paleozoic to Precambrian in source terrains, though age cannot be determined visually.

Uses & applications

Used as a decorative tumbled stone, cabochon, paperweight, or landscaping material; generally not a high-value gemstone.

Geological facts

Its green color commonly reflects chlorite and epidote rather than copper minerals. A glassy surface here is produced by polishing, not natural luster.

Field identification & locations

Common in stream gravels and metamorphic belts; identify with a streak, hardness, and magnetism test, and inspect under magnification for epidote or amphibole grains. It could also be serpentine or nephrite, which require testing to distinguish.