Rock Identifier
Rounded greenish river pebble (Likely altered basalt or greenstone (metabasalt); exact identification requires testing) — igneous
igneous

Rounded greenish river pebble

Likely altered basalt or greenstone (metabasalt); exact identification requires testing

AI-generated identification · may be incorrect

Fine-grained, dull to slightly waxy luster, gray-green and brown coloration, smoothly water-worn; likely Mohs 5–6, with no visible cleavage and interlocking microscopic crystals. Composition may include plagioclase, pyroxene, chlorite, epidote, and iron oxides.

Identified More igneous
Explore Rounded greenish river pebble in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

Physical properties

Fine-grained, dull to slightly waxy luster, gray-green and brown coloration, smoothly water-worn; likely Mohs 5–6, with no visible cleavage and interlocking microscopic crystals. Composition may include plagioclase, pyroxene, chlorite, epidote, and iron oxides.

Formation & geological history

Probably basaltic volcanic rock later altered by low-grade metamorphism and rounded by stream or beach transport. Basaltic protoliths commonly formed from oceanic or continental lava, generally from ancient to geologically recent ages.

Uses & applications

Suitable mainly as a landscaping, craft, or decorative stone; not typically valuable for jewelry or construction because the specimen is small and nondescript.

Geological facts

Green coloration commonly reflects chlorite or epidote alteration rather than a single green mineral. A streak, hardness, magnetism, and fresh-break examination would improve identification.

Field identification & locations

Common in riverbeds, beaches, glacial deposits, and areas containing basalt or metamorphosed oceanic crust; identify by its dense, fine texture, rounded shape, and green-gray color. Estimated value: $1–$10 as a common specimen.