metamorphic

Schist (Greenschist / Mica Schist)

Foliated Metamorphic Rock (rich in chlorite, muscovite, and quartz)

AI-generated identification · may be incorrect

Hardness variable (3.5 to 6 on Mohs scale), greenish-grey to silver color, vitreous to pearly/silky luster due to mica grains, distinct parallel foliation (schistosity), platy or sheet-like cleavage.

Identified July 27, 2026More metamorphic →

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Physical properties

Hardness variable (3.5 to 6 on Mohs scale), greenish-grey to silver color, vitreous to pearly/silky luster due to mica grains, distinct parallel foliation (schistosity), platy or sheet-like cleavage.

Formation & geological history

Formed under regional metamorphism from low-to-medium grade pressure and temperature, typically originating from mudstone, shale, or basalt precursors in convergent tectonic plate boundaries.

Uses & applications

Used historically as dimension stone, flagstone, decorative landscaping stone, and occasionally as minor construction aggregate or carving material.

Geological facts

Schist is characterized by having medium-to-large flat sheet-like grains in a preferred orientation. The word 'schist' derives from the Greek word 'schizein', meaning 'to split', referring to its ease of splitting along platy mineral layers.

Field identification & locations

Identify by looking for shiny, aligned flaky minerals (mica, chlorite) causing a reflective, layered appearance along breaking planes. Common in mountain belts such as the Appalachians, Alps, and Himalayas.