Phosphates are salts or esters of phosphoric acid. The most important inorganic phosphate is calcium phosphate. It makes up the larger part of phosphate rock, a mineral that is abundantly distributed throughout the world. Another important inorganic phosphate is sodium phosphate, used in detergents, for softening water, and to some extent in medicine and in preparing baking powders. Various acid phosphates such as calcium, magnesium, and sodium are sometimes present in carbonated beverages. Organic phosphates play an important role in metabolism. Nucleotides are phosphate esters that play an important role in the conservation and use of the energy released in the metabolism of foods in the body. DNA and RNA are complex polymeric organic phosphates.
Phosphates are the naturally occurring form of the element phosphorus. In mineralogy and geology, phosphate refers to a rock or ore containing phosphate ions. Inorganic phosphates are mined to obtain phosphorus for use in agriculture and industry. The largest phosphorite or rock phosphate deposits in United States, lie in the Bone Valley region of central Florida, the Soda Springs region of Idaho, and the coast of North Carolina. Smaller deposits are located in Montana, Tennessee, Georgia and South Carolina near Charleston along Ashley Phosphate road. The small island nation of Nauru and its neighbor Banaba Island, which used to have massive high quality phosphate deposits, have been mined excessively. Rock phosphate can also be found in Egypt, Israel, Morocco, Navassa Island, Tunisia, Togo and Jordan.