metamorphic
Mica Schist
Schist (muscovite-biotite schist)
Hardness: 3.5-4; Color: Silver, gray, or medium to dark green; Luster: Silky to pearly/metallic; Structure: Foliated with visible mica flakes; Cleavage: Perfect basal cleavage on individual mica crystals; Specific Gravity: 2.7-3.0
- Hardness
- 3
- Color
- Silver, gray, or medium to dark green
- Luster
- Silky to pearly/metallic
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 3.5-4; Color: Silver, gray, or medium to dark green; Luster: Silky to pearly/metallic; Structure: Foliated with visible mica flakes; Cleavage: Perfect basal cleavage on individual mica crystals; Specific Gravity: 2.7-3.0
Formation & geological history
Formed through regional metamorphism of shale or mudstone under intermediate to high temperatures and pressures, causing clay minerals to recrystallize into larger mica plates.
Uses & applications
Used occasionally as decorative stone for gardens or facades, and historically as a filler in construction materials. Often a source of industrial mica for high-temperature insulation.
Geological facts
The term 'schist' is derived from the Greek word 'schistos', meaning 'split', referring to the rock's tendency to split into thin layers. Schist is an indicator of the 'metamorphic grade' and falls between phyllite and gneiss.
Field identification & locations
Identify by its distinct glittery/shimmery surface (schistosity) and wrinkled foliation planes. Commonly found in metamorphic mountain belts like the Appalachian Mountains or the Alps.
More like this
