Mica Schist with Quartz

Physical Properties

Hardness: 2-3 (mica) and 7 (quartz), Color: Silvery-gray with white inclusions, Luster: Pearly to sub-metallic (mica) and vitreous (quartz), Crystal Structure: Monoclinic/Hexagonal, Cleavage: Perfect basal (mica)

Formation & Geological History

Formed through high-grade regional metamorphism of clay-rich sedimentary rocks (shales) under high temperature and pressure environments. Common in orogenic belts (mountain-building zones).

Uses & Applications

Primarily used as a decorative stone, in construction aggregates, and as a source for ground mica used in paints, cosmetics, and electrical insulation.

Geological Facts

The 'shiny' effect is caused by muscovite mica flakes reflecting light. This specimen shows a transition where quartz veins have intruded or segregated during the metamorphic process.

Field Identification & Locations

Identify by its 'schistosity' (pronounced layering/alignment of minerals) and intense sparkle when rotated in light. Found in metamorphic terrains like the Appalachians or the Alps.

Identified on: 4/29/2026

Mode: Standard