Rock salt, or halite, is the mineral form of sodium chloride (\(NaCl\)) that exists as large, solid deposits. It forms from the evaporation of saltwater and is often colored white, pink, blue, or gray due to impurities, with brown being a common color. Rock salt is used for various applications, including de-icing roads, as a seasoning and source of trace elements in food, and in many industrial processes.