Salt is the common name for the mineral deposit sodium chloride, found in solids as rock salt and in diluted form as brine, for example in sea water.
An essential ingredient in the human diet, salt provides minerals and is added to foods, during cooking as well as at the table, mainly to bring out and enhance flavour. Salt is also added to water used to clean vegetables as it helps to remove any small insects.
Salt may be bought commercially pro-cessed as table salt, and in its natural forms of rock salt and sea salt.
Rock salt is mined in beds in its crystal-line structure, though deposits are be-coming increasingly rare and difficult to work. After mining, the salt is purified and crushed, and then graded.
Salt obtained from sea water and brine wells is more readily available. The brine solution is purified and the water evap-orated, and the salt is then graded, the best quality being reserved for table salt and cooking, while lower quality grades are used in commercial chemical and preserving industries, and in ice-cream churns for freezing.
Salt absorbs the moisture in the atmos-phere very easily and should be stored in a dry place. For this reason, table salt usually contains a small quantity of magnesium carbonate and calcium phos-phate to help keep it dry.