metamorphic

Weathered greenstone pebble

Likely chlorite–actinolite schist or altered basalt; exact identification requires testing

AI-generated identification · may be incorrect

Fine- to medium-grained, rounded pebble with mottled green, cream, gray, and rusty-brown surfaces; likely dull to weakly waxy luster, Mohs hardness about 5–6, with no obvious cleavage visible. Green color commonly reflects chlorite, epidote, actinolite, or altered mafic minerals.

Identified September 10, 2026More metamorphic →

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Physical properties

Formation & geological history

Probably a glacially or stream-rounded fragment of metamorphosed or hydrothermally altered basalt, formed during ancient metamorphism and later weathered at the surface. Geological age cannot be determined from the photograph.

Uses & applications

Commonly used as landscaping or decorative stone; attractive pieces may be collected or polished, but this specimen has modest commercial value.

Geological facts

Its rusty patches are likely iron-oxide weathering, while pale areas may be quartz, feldspar, or epidote. A magnet, streak, hardness, and thin-section examination could substantially refine identification.

Field identification & locations

Common in areas containing greenstone belts, altered volcanic rocks, and glacial or river gravels. Test for a greenish-gray streak, hardness near glass, and possible weak magnetism; natural weathering and rounded edges support a transported pebble.