halite (rock salt) 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 …Web