metamorphic
Schist
Mica Schist
Hardness: 3.5-4; Color: Silvery-gray, black, or dark green; Luster: Pearly to submetallic; Crystal Structure: Foliated (schistose); Cleavage: Excellent in one direction along mica flakes; Specific Gravity: 2.7-2.8
- Hardness
- 3
- Color
- Silvery-gray, black, or dark green
- Luster
- Pearly to submetallic
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 3.5-4; Color: Silvery-gray, black, or dark green; Luster: Pearly to submetallic; Crystal Structure: Foliated (schistose); Cleavage: Excellent in one direction along mica flakes; Specific Gravity: 2.7-2.8
Formation & geological history
Formed through the regional metamorphism of shale or mudstone under intermediate to high temperatures and pressures. Most date back to the Proterozoic or Paleozoic eras.
Uses & applications
Used as a decorative stone in architecture, for walling, flagstones, and occasionally as a source of industrial minerals like garnet or graphite found within the rock.
Geological facts
The word 'schist' is derived from the Greek meaning 'to split,' referring to its ease of splitting along the planes of mica flakes. It is the intermediate stage between phyllite and gneiss.
Field identification & locations
Identify by its sparkly, 'glittery' appearance caused by the alignment of visible mica flakes and its ability to split into thin sheets. Commonly found in mountain ranges like the Appalachians or Alps.
More like this
