Mica Schist

Physical Properties

Hardness: 2-2.5 (Mohs), Color: silvery-gray to brownish-brass, Luster: Pearly to metallic (highly reflective), Crystal Structure: Monoclinic, Cleavage: perfect basal (sheets), Specific Gravity: 2.7–3.0.

Formation & Geological History

Formed through the regional metamorphism of shale or mudstone under medium-grade heat and pressure. It contains visible platy mineral grains like muscovite or biotite that have aligned to create a 'schistose' texture.

Uses & Applications

Used as filler in paints and plastics, as a decorative stone in gardening, and occasionally in construction for roofing or flooring tiles. It is primarily a collector specimen for its sparkle.

Geological Facts

Mica was often used as window panes for ovens and furnaces before modern glass because it can withstand high heat without melting. Its name is derived from the Latin word 'micare', meaning 'to shine'.

Field Identification & Locations

Identify in the field by its distinct foliation (layering) and the presence of flat, shiny flakes that easily peel off with a fingernail or knife. Commonly found in mountainous regions or ancient crystalline shield areas.

Identified on: 4/16/2026

Mode: Standard