metamorphic
Schist
Chlorite-Mica Schist
Hardness: 3.5-5; Color: Greenish-gray with silver sheen; Luster: Pearly to sub-metallic; Crystal structure: Sheet-like (foliated); Cleavage: Perfect in one direction (slaty/schistose); Specific gravity: 2.7-2.9
- Hardness
- 3
- Color
- Greenish-gray with silver sheen
- Luster
- Pearly to sub-metallic
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 3.5-5; Color: Greenish-gray with silver sheen; Luster: Pearly to sub-metallic; Crystal structure: Sheet-like (foliated); Cleavage: Perfect in one direction (slaty/schistose); Specific gravity: 2.7-2.9
Formation & geological history
Formed through the regional metamorphism of shale or mudstone under intermediate to high temperatures and pressures, typically during orogenic (mountain-building) events.
Uses & applications
Historically used for flagstones, decorative building stone, and occasionally as a source of graphite or certain industrial minerals. Small river-tumbled pieces are primarily used for education or personal collections.
Geological facts
The word 'schist' is derived from the Greek word 'schizein', meaning 'to split', referring to the ease with which these rocks can be layered or split. It is often filled with accessory minerals like garnets or staurolite.
Field identification & locations
Identify by its distinct 'schistosity' or layered, glittery appearance. It is commonly found in crystalline basement rocks of mountain ranges like the Appalachians or the Alps. Look for the alignment of mica flakes which create its characteristic shine.
More like this
