metamorphic
Greenschist
Greenschist (Chlorite-actinolite schist)
Hardness: 3.5-4.5 on Mohs scale; Color: Greenish-grey with mottled tan patches; Luster: Dull to silky; Crystal Structure: Foliated/Schistose; Cleavage: Good in one direction; Specific Gravity: 2.8-3.3
- Hardness
- 3
- Color
- Greenish-grey with mottled tan patches
- Luster
- Dull to silky
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 3.5-4.5 on Mohs scale; Color: Greenish-grey with mottled tan patches; Luster: Dull to silky; Crystal Structure: Foliated/Schistose; Cleavage: Good in one direction; Specific Gravity: 2.8-3.3
Formation & geological history
Formed through regional metamorphism of mafic igneous rocks (like basalt) under low-temperature (200-450 C) and moderate-pressure conditions. Usually associated with orogenic belts.
Uses & applications
Used as decorative stone in gardens, for architectural facings, and occasionally as a source for minor minerals or construction aggregate.
Geological facts
The green color is primarily due to minerals like chlorite, epidote, and actinolite. The name 'greenschist' refers specifically to the green color and the schistose (layered) texture.
Field identification & locations
Look for the characteristic green hue and fine-grained, foliated layers that may appear platy. It is common in ancient mountain belts and coastal regions where oceanic crust has been subducted.
More like this
