Mineral, NaCl; sp. gr. 2.2; hardness 2.5; cubic; perfect cubic cleavage; colourless, white, or shades of yellow, red, and blue; white streak; vitreous lustre; crystals usually cubes, often with curved faces, but it can be granular and compact; widely distributed in stratified evaporite deposits, associated with other water-soluble minerals (e.g. sylvite) and with gypsum and anhydrite of various geologic ages, large masses frequently forming plugs which rise through and arch overlying sedimentary rocks, thereby forming oil traps; soluble in water; tastes salty. It is widely used as a road dressing in icy weather.
Subjects: Earth Sciences and Geography.