metamorphic
Schist
Mica Schist
Hardness (Mohs scale): 3.5-5; Color: Grey, silver, or greenish; Luster: Submetallic to silky; Crystal structure: Foliated; Cleavage: Excellent in one direction due to mica alignment; Specific gravity: 2.7–2.8
- Color
- Grey, silver, or greenish
- Luster
- Submetallic to silky
Identified More metamorphic →
Explore Schist in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness (Mohs scale): 3.5-5; Color: Grey, silver, or greenish; Luster: Submetallic to silky; Crystal structure: Foliated; Cleavage: Excellent in one direction due to mica alignment; Specific gravity: 2.7–2.8
Formation & geological history
Formed from the regional metamorphism of shale or clay minerals at medium temperature and pressure. It often dates back to various tectonic events throughout Earth's history, typically occurring at convergent plate boundaries.
Uses & applications
Used primarily as decorative stone, in landscaping, flagstone for walkways, and occasionally as a source of industrial mica or garnets if present.
Geological facts
The word 'schist' is derived from the Greek word 'schizein', meaning 'to split', referring to the ease with which the rock can be split along its aligned minerals.
Field identification & locations
Identify by its 'schistosity' or layered, glittery appearance caused by large mica flakes. Common in mountain ranges like the Appalachians or the Alps. Look for the distinct way it catches the light when rotated.
More like this
