Schist is a type of metamorphic rock that displays a tendency to split into thin layers or flakes. Its name also has Greek roots, evolving from skhistos, meaning “split” or “divisible.” The majority of schists are composed of platy minerals, such as graphite and muscovite, and most exhibit extreme foliation or banding. Schists are particularly abundant among Precambrian rocks and are generally classified according to their mineralogy.