metamorphic

Greenschist

Greenschist (Chlorite-actinolite schist)

AI-generated identification · may be incorrect

Hardness: 3.5-4.5; Color: Dark green to grey-green; Luster: Dull to silky; Crystal Structure: Foliated; Cleavage: Good in one direction; Specific Gravity: 2.8-3.0

Hardness: 3
Color: Dark green to grey-green
Luster: Dull to silky

Identified July 12, 2026More metamorphic →

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Physical properties

Hardness: 3.5-4.5; Color: Dark green to grey-green; Luster: Dull to silky; Crystal Structure: Foliated; Cleavage: Good in one direction; Specific Gravity: 2.8-3.0

Formation & geological history

Formed through low-temperature, high-pressure metamorphism (greenschist facies) of mafic igneous rocks like basalt or gabbro, typically during mountain-building events.

Uses & applications

Mainly used for decorative stone in gardens, historical building material, and occasionally as a source for crushed stone in construction.

Geological facts

The green color is primarily due to the presence of minerals like chlorite, epidote, and actinolite. It is a key indicator of the metamorphic grade of a region.

Field identification & locations

Identify by its characteristic green hue and fine-grained, foliated (layered) texture. Common in ancient mountain belts such as the Appalachians or the Scottish Highlands.