Visit the  Salt Institute  for more information about salt.

What Is Salt ? 

Salt is a mineral composed of sodium and chlorine. Neither can exist alone in natural form. Together, they form the chemical compound that is sodium chloride. To geologists, salt is known as halite.
Salt is a crystal of the isometric system, meaning it is usually cubic and perfectly symmetrical. Pure salt crystals are colorless, although a pile of them will appear to be white. Impurities in the crystals may cause salt to be various shades of yellow, red, blue or purple.
Today there are more than 14,000 uses for salt in industry, in medicine and in the home. The majority of salt sold today is used to deice roads and highways to provide safer driving conditions in winter weather, which, in turn, keeps businesses running so the economy is not hampered. However, salt is also used to soften hard water, provide nutrition to livestock, and in many industrial applications. It plays a vital role as a raw material in chemical manufacturing. And it also is the only rock we eat.