Schist \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.

Source: Webster's Revised Unabridged Dictionary (1913)