metamorphic
Mica Schist
Mica Schist (primarily Muscovite and/or Biotite Schist)
Hardness: 2.5-4; Color: Silvery-gray, greenish-gray, or brown; Luster: Pearly to metallic; Structure: Schistose foliation with visible flakes; Cleavage: Perfect basal cleavage in mica flakes; Specific Gravity: 2.7-3.0.
- Hardness
- 2
- Color
- Silvery-gray, greenish-gray, or brown
- Luster
- Pearly to metallic
Identified More metamorphic →
Explore Mica Schist in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 2.5-4; Color: Silvery-gray, greenish-gray, or brown; Luster: Pearly to metallic; Structure: Schistose foliation with visible flakes; Cleavage: Perfect basal cleavage in mica flakes; Specific Gravity: 2.7-3.0.
Formation & geological history
Forms from the regional metamorphism of shale or mudstone under medium-grade temperatures and pressures. Most common in Precambrian and Paleozoic mountain belts.
Uses & applications
Used as decorative stone in landscaping, flagstone for walkways, and occasionally as a source of scrap mica for insulation and joint compounds.
Geological facts
The word 'schist' comes from the Greek word 'schizein', meaning 'to split', referring to how easily the rock breaks along its foliated mineral layers. Its glittery appearance is due to the alignment of flat mica crystals.
Field identification & locations
Identified by its shiny, flaky, 'glittering' surface and tendency to split into thin plates. Commonly found in metamorphic terrains like the Appalachian or Himalayan mountains. Collectors look for accessory minerals like garnet within the schist.
