a common mineral, potassium chloride, KCl, colorless to milky-white or red, occurring in crystals, usually cubes, and masses with cubic cleavage, bitter in taste: the most important source of potassium.
a soluble colourless, white, or coloured mineral consisting of potassium chloride in cubic crystalline form with sodium impurities: it occurs chiefly in sedimentary beds and is an important ore of potassium. Formula: KCl
C19: sylvite, alteration of sylvine, from New Latin sal digestiva Sylvii digestive salt of Sylvius, after Franciscus Sylvius (died 1672), German anatomist. See -ite1, -ine²