Borax (also know as sodium borate, disodium tetraborate, and sodium tetraborate) is a white, crystalline compound. It is naturally occurring, and can be mined in some places like California. This alkaline substance has been used for numerous purposes through many centuries. It is perhaps best known as a cleaning agent, although it is also sometimes used in tanning, and in manufacture of glass, metals (as a flux), porcelain, and enamel. It can also be used as a preservative, a mild antiseptic, and even for therapeutic purposes, although this is banned in several countries, including the United States.