metamorphic
Schist
Mica Schist (Metamorphic Rock)
Hardness: 3.5-4; Color: Silvery-gray, brownish, or golden; Luster: Pearly to sub-metallic due to mica flakes; Structure: Foliated with large, visible mineral grains; Cleavage: Excellent basal cleavage in mica components.
- Hardness
- 3
- Color
- Silvery-gray, brownish, or golden
- Luster
- Pearly to sub-metallic due to mica flakes
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: 3.5-4; Color: Silvery-gray, brownish, or golden; Luster: Pearly to sub-metallic due to mica flakes; Structure: Foliated with large, visible mineral grains; Cleavage: Excellent basal cleavage in mica components.
Formation & geological history
Formed through the regional metamorphism of shale or mudstone under high temperature and pressure. It represents an intermediate grade of metamorphism between phyllite and gneiss.
Uses & applications
Used historically as a building stone for walls and decorative flagging. Some varieties are sources of industrial minerals like garnet or graphite. In modern times, it is used for garden landscaping and occasionally as dimensional stone.
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 plates. The flashy, glittery appearance is caused by the alignment of plate-like mica minerals.
Field identification & locations
Identify in the field by its strong foliation (schistosity) and 'glittery' appearance under sunlight. Common in mountain ranges and eroded shield areas. Collectors value it for included crystals like garnets.
More like this
