![Mica Schist (Mica Schist (primarily Muscovite [KAl2(AlSi3O10)(OH)2] or Biotite)) — metamorphic](https://media.rockidentification.com/a0db59d4-d397-461c-9a00-04eeb2a204b4-compressed.jpg)
metamorphic
Mica Schist
Mica Schist (primarily Muscovite [KAl2(AlSi3O10)(OH)2] or Biotite)
Hardness: 2-3 (on the Mohs scale for the mica component); Color: Silvery-gray, greenish, or silvery-white; Luster: Pearly to metallic; Crystal structure: Monoclinic (platey/lamellar); Cleavage: Perfect basal cleavage; Specific Gravity: 2.7–3.0
- Hardness
- 2-3 (on the Mohs scale for the mica component)
- Color
- Silvery-gray, greenish, or silvery-white
- Luster
- Pearly to metallic
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 2-3 (on the Mohs scale for the mica component); Color: Silvery-gray, greenish, or silvery-white; Luster: Pearly to metallic; Crystal structure: Monoclinic (platey/lamellar); Cleavage: Perfect basal cleavage; Specific Gravity: 2.7–3.0
Formation & geological history
Formed from the regional metamorphism of shale or mudstone at intermediate temperatures and pressures. This transformation typically occurs during mountain-building events (orogenies) over millions of years.
Uses & applications
Used primarily in construction for decorative stone (veneer), roofing materials, and occasionally as a source of ground mica for lubricants, glitter, or filler in paints and plastics.
Geological facts
The word 'schist' is derived from the Greek word 'schistos', meaning 'split', referring to the rock's characteristic of splitting easily into thin plates. It represents a higher grade of metamorphism than slate or phyllite.
Field identification & locations
Identify in the field by its 'schistosity'—a sparkly, foliated texture where individual mica flakes are visible to the naked eye. Commonly found in metamorphic belts like the Appalachian Mountains, the Scottish Highlands, and the Alps. Collectors should look for garnets which often grow within the mica layers.
More like this
