Salt beds are one of the Earth's greatest sources of inorganic chemical compounds.

Salt deposits, which exist on every continent on Earth, are mineral residues left behind after salt-rich bodies of water evaporated long ago.

The Dead Sea and the Great Salt Lake are current examples of salt accumulating as a body of water evaporates.

In addition to table salt, salt beds are rich in potash, an agricultural fertilizer; sodium salts used in manufacturing soaps and paper; gypsum, the basis of plaster of Paris, and a wide range of rarer chemicals used in industry.

Salt deposits are often found in deserts.

Nitrates, the basis of fertilizers and explosives, can be found in Chile's Atacama Desert.

The borates of the western northern American desert are used in the enamel and glass industries.

The deposits became concentrated in the desert floor by the upward percolation of mineral springs over the ages. They have remained in place because there is little or no rain to wash them away.