metamorphic
Schist
Mica Schist (Metamorphic rock)
Hardness: 3.5–4.0; Color: Silvery-gray, greenish, or brownish; Luster: Pearly to sub-metallic due to mica; Structure: Foliated with visible mineral grains; Cleavage: Perfect basal cleavage in individual flakes.
- Hardness
- 3
- Color
- Silvery-gray, greenish, or brownish
- Luster
- Pearly to sub-metallic due to mica
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: 3.5–4.0; Color: Silvery-gray, greenish, or brownish; Luster: Pearly to sub-metallic due to mica; Structure: Foliated with visible mineral grains; Cleavage: Perfect basal cleavage in individual flakes.
Formation & geological history
Formed by the regional metamorphism of clay-rich sedimentary rocks (like shale or mudstone) or certain igneous rocks under high pressure and temperature conditions. It typically represents a medium-grade metamorphism level (higher than phyllite but lower than gneiss).
Uses & applications
Used historically as a building stone for foundations and walls; sometimes used in landscaping or as crushed stone for road construction.
Geological facts
Schist is characterized by 'schistosity,' a parallel arrangement of platy minerals like muscovite or biotite that allows the rock to split into thin layers. It often contains accessory minerals like garnets.
Field identification & locations
Identify by its sparkling, 'glittery' appearance under sunlight and its tendency to flake or split into thin sheets. It is commonly found in mountain ranges and metamorphic terranes throughout the Appalachian Mountains and the Alps.
More like this
