Rock Salt or Halite

Rock salt has a typical way of crystallising known as “hopper” crystallisation, that is, cubic crystals with stepped, hollowed faces, caused by irregular growth. It sometimes also occurs in compact and granular aggregates. When perfectly pure it is colourless; otherwise it can be white, orange, yellow, pink, blue or violet. Transparent to translucent, this mineral is soft, very light and brittle. Rock salt is soluble in water, to which it gives a slightly salty taste, and is damp to the touch.

It forms in sedimentary deposits derived from the evaporation of the waters of salt lakes, It is often found associated with other evaporite minerals (gypsum, anhydrite, dolomite, etc.).

Rock salt is used mainly as a food component in the canning industry. In the chemical industry it is used for the production of soda and hydrochloric acid.