schist : Idioms & Phrases


alum schist

Al"um schist", Al"um shale" (Also<
  • Alum schist
  • Alum shale
)
Definitions
  1. (Min.) A variety of shale or clay slate, containing iron pyrites, the decomposition of which leads to the formation of alum, which often effloresces on the rock.
Webster 1913

Argillaceous schist or state

  • . See Argillite.
Webster 1913

Hornblende schist

  • (Geol.), a hornblende rock of schistose structure.
Webster 1913

Hydromica schist

  • (Min.), a mica schist characterized by the presence of hydromica. It often has a silky luster and almost soapy feel.
Webster 1913

Mica schist, Mica slate

  • (Geol.), a schistose rock, consisting of mica and quartz with, usually, some feldspar.
Webster 1913