metamorphic
Schist
Mica Schist
Hardness: 3.5-4; Color: Silvery-gray, charcoal, or dark green; Luster: Pearly to submetallic due to mica content; Crystal structure: Foliated (schistosity); Cleavage: Perfect basal cleavage in individual mineral grains; Specific Gravity: 2.7-2.8
- Hardness
- 3
- Color
- Silvery-gray, charcoal, or dark green
- Luster
- Pearly to submetallic due to mica content
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 3.5-4; Color: Silvery-gray, charcoal, or dark green; Luster: Pearly to submetallic due to mica content; Crystal structure: Foliated (schistosity); Cleavage: Perfect basal cleavage in individual mineral grains; Specific Gravity: 2.7-2.8
Formation & geological history
Formed through the regional metamorphism of shale or mudstone at medium grades (temperatures and pressures). It is characterized by the alignment of plate-like minerals such as muscovite and biotite.
Uses & applications
Used primarily in construction for paving, flags, and building stone. Because of its reflective properties, it is sometimes used as a decorative stone in gardens or interior cladding.
Geological facts
The word 'schist' is derived from the Greek 'schizein', meaning 'to split', referring to the ease with which the rock can be divided into thin plates along its foliation.
Field identification & locations
Identify in the field by looking for a 'shiny' or 'glittery' appearance on flat surfaces caused by mica flakes and a distinct layered/foliated texture. It is common in mountain ranges like the Appalachians or Alps.
More like this
