Lithium is used in special glasses and ceramics. The glass for the 200-inch telescope at Mt. Palomar contains lithium as a minor ingredient. Lithium chloride is one of the most hygroscopic materials known, and it, as well as lithium bromide, is used in air conditioning and industrial drying systems. Other lithium compounds are used in dry cells and storage batteries. Seven isotopes of lithium are recognized.
Natural lithium contains two isotopes.