metamorphic
Mica Schist
Mica Schist (KAl2(AlSi3O10)(OH)2)
Hardness: 2-4 on Mohs scale; Color: Silvery-gray, bronze, or golden-brown; Luster: Pearly to Vitreous/Metallic; Crystal Structure: Monoclinic; Cleavage: Perfect basal cleavage in individual mica grains; Texture: Foliated (schistosity).
- Hardness
- 2-4 on Mohs scale
- Color
- Silvery-gray, bronze, or golden-brown
- Luster
- Pearly to Vitreous/Metallic
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 2-4 on Mohs scale; Color: Silvery-gray, bronze, or golden-brown; Luster: Pearly to Vitreous/Metallic; Crystal Structure: Monoclinic; Cleavage: Perfect basal cleavage in individual mica grains; Texture: Foliated (schistosity).
Formation & geological history
Forms through the regional metamorphism of shale or clay-rich sedimentary rocks under intermediate to high temperature and pressure. The alignment of mica minerals gives it a characteristic sparkle.
Uses & applications
Primarily used as a decorative stone in landscaping, flagstone for walkways, and as a source of scrap mica for insulation or as a filler in plaster and paint.
Geological facts
The term 'schist' is derived from the Greek word 'schistos', meaning 'split', referring to the ease with which these rocks can be divided into thin layers. Large mica sheets were historically used for furnace windows.
Field identification & locations
Identifiable by its strong foliation and prominent glistening mica flakes that reflect light easily. Found in mountain belts like the Appalachians, Alps, or Himalayas. Collectors look for large garnet inclusions often found within it.
More like this
