A highly foliated, medium-grained metamorphic rock that splits easily into flakes or slabs along well-defined planes of mica. The mineral composition of schist is varied and is often reflected in the name given to the rock. For example, a schist that contains garnet is called a garnet schist. A schist containing chlorite is called a chlorite schist.
schistose adjective (shĭs'tōs')