Schist

Foliated texture, shiny/glittery appearance due to mica flakes (muscovite or biotite), hardness varies (typically around 3-4 for mica), silvery to gray or brown color, vitreous to pearly luster.

Formed by regional metamorphism of shale or mudstone under medium temperature and pressure. The alignment of plate-like minerals (like mica) creates the characteristic foliation (schistosity).

Often used as a decorative building stone, in landscaping, and sometimes as a source of industrial minerals (like garnet or mica) if present in high concentrations.

The word 'schist' comes from a Greek word meaning 'to split', referring to the rock's tendency to break along its foliated planes. Schist can contain large, noticeable crystals of minerals like garnet, staurolite, or kyanite (porphyroblasts).

Identify in the field by its strong foliation (schistosity) and the visible, shiny flakes of mica that are aligned parallel to each other. Commonly found in mountain belts where regional metamorphism has occurred.