\Schist\ (sh[i^]st), n. [Gr. ? divided, divisible, fr. ? to divide: cf. F. schiste. See {Schism}.] (Geol.) Any crystalline rock having a foliated structure (see {Foliation}) and hence admitting of ready division into slabs or slates. The common kinds are mica schist, and hornblendic schist, consisting chiefly of quartz with mica or hornblende and often feldspar.