Borax

Borax, common name for a hydrated form of sodium borate or sodium tetraborate, a white powder that becomes transparent and glasslike when heated. Borax is used in glazes and in the manufacture of ceramics and heat-resistant glass. In metallurgy it is used to remove oxide slags. Borax “beads” are used as a test for metals in chemical analysis. Large quantities of borax in the form of the mineral tincal come from Searle's Lake, Ca.

See also: Boric acid; Boron.