Sodium chloride or common salt is the compound NaCl. It occurs naturally in many parts of the world as the mineral halite. Underground salt deposits are sedimentary in origin. Salt occurs in beds and in dome-like deposits. The primary source of all salt deposits is the world's oceans.
Salt even arrives on earth from outer space.
Salt is sold in several different particle sizes grades and forms, depending on the intended end use. Discrete crystals can be seen in rock salt and solar salt used for deicing roads. Fine granules are typical of table salt and even finer popcorn salt. Kosher salt, canning and pickling salt and ice cream salt are slightly coarser. Small compressed pellets are used in water softeners and large salt blocks are used as salt licks for livestock and in some water softeners.