metamorphic

Greenstone (likely greenschist)

Chlorite–actinolite–epidote-rich metabasalt; mineral proportions cannot be confirmed from the photo

AI-generated identification · may be incorrect

Fine-grained, rounded green pebble with pale mineral flecks and a dull to slightly silky surface. Likely Mohs hardness about 5–6; exact composition and properties require testing.

Identified September 28, 2026More metamorphic →

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Physical properties

Fine-grained, rounded green pebble with pale mineral flecks and a dull to slightly silky surface. Likely Mohs hardness about 5–6; exact composition and properties require testing.

Formation & geological history

Typically forms when basalt or related mafic volcanic rock is metamorphosed under low-grade, water-rich conditions. Its age depends on the source geology and cannot be determined visually.

Uses & applications

Commonly collected as a pebble or specimen; greenstone is also used locally as decorative stone and, when suitable, for carving.

Geological facts

“Greenstone” is a field term for several green metamorphic rocks, not one uniquely defined mineral or rock composition.

Field identification & locations

Look for a dense, fine-grained green rock, often with chlorite, epidote, or amphibole; the rounded shape suggests water transport. Greenstone occurs in metamorphic belts worldwide, but a photo alone cannot establish a precise identification or locality.