Salt is also used to cure animal hides and to remove ice and snow from pavements. Water-softening equipment uses salt, and salt is indispensable in the manufacture of certain chemicals. Physically, table salt occurs as a cube-shaped crystal that, depending on purity, may be colorless, transparent, or translucent. Under normal conditions, salt will absorb water from the atmosphere. It also dissolves easily in water, and as it does so, it lowers the water's temperature.
Sodium chloride is by far the most common salt that exists naturally on the Earth.
These naturally occurring deposits of water with an unusually high percentage of salt are called brines. They include the Dead Sea, the Great Salt Lake, and other deposits in various parts of the United States, Great Britain, Germany, France, Austria, and India. These deposits are the products of the evaporation of seas in the distant past. They may occur as beds that lie on or near the Earth's surface or as deposits deep underground. Another major source of rock salt is salt domes, vertical cylinders of rock salt embedded in surrounding layers of earth.