Mica Schist

Physical Properties

Hardness: 3.5-4 (Mohs scale); Color: Silver, grey, or greenish-grey; Luster: Pearly to sub-metallic; Crystal structure: Foliated; Cleavage: Perfect basal cleavage in individual mica grains; Specific gravity: 2.7-3.0

Formation & Geological History

Formed through the regional metamorphism of shale or mudstone at medium-grade temperatures and pressures. This specimen displays prominent foliation from the alignment of platy mica minerals.

Uses & Applications

Used primarily for decorative purposes, landscape stone, and occasionally as a source for ground mica in industrial applications like fillers or roof shingles.

Geological Facts

The word 'schist' is derived from the Greek word 'schizein', which means 'to split', referring to the rock's tendency to split easily along its foliation planes.

Field Identification & Locations

Look for a shiny, 'glittery' appearance due to the high mica content and a distinct layered or wavy foliated texture. Common in ancient mountain belts.

Identified on: 5/11/2026

Mode: Standard