Sylvite - KCl

Habit: Cubic, cubo-octahedra and octahedra crystals. May be columnar, in crusts, coarse granular to compact, massive. Colorless to white, pale blue, pale blue-gray, yellowish-red, to red when included with hematite. Vitreous Luster, transparent.

Environment: In sedimentary basins, forming thick bedded deposits with halite. As a sublimate in volcanic fumaroles and cave deposits.

Etymology: From the name sal disgestivus Sylvii or digestive salt, an old chemical name for the substance named by Francois Sylvius de le Boe (1614-1672), Dutch physician and chemist from the Netherlands.