metamorphic

Greenstone / epidote–chlorite schist (tentative)

Epidote–chlorite schist, likely containing actinolite and quartz/feldspar

AI-generated identification · may be incorrect

Fine- to medium-grained, mottled dark green and reddish-brown, with a dull to weakly pearly luster and possible foliation. Typical hardness is about 5–6.5 Mohs; cleavage is weak to moderate along schistose layers, and specific gravity is roughly 2.8–3.4.

Identified September 12, 2026More metamorphic →

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Physical properties

Formation & geological history

Formed when basaltic or volcanic parent rock was metamorphosed under greenschist- to lower-amphibolite-facies conditions, commonly during mountain building. Its exact geological age cannot be determined from the photograph.

Uses & applications

Used locally as decorative stone, aggregate, or lapidary material; attractive pieces may be polished, but it is not usually a high-value gemstone.

Geological facts

The green color commonly reflects chlorite, epidote, actinolite, or serpentine. The reddish-brown areas may be iron oxides or weathered feldspar/minerals.

Field identification & locations

Look for visible foliation, a granular interlocking texture, green metamorphic minerals, and greater toughness than soft massive stone; a streak, hardness, acid, and thin-section test would refine identification. Common in metamorphic belts worldwide, including the Alps, Appalachians, and Pacific-margin ranges.