Borax Decahydrate is the refined form of natural sodium borate. Composed of boric oxide (B2O3), sodium oxide, and water, it is a mild, alkaline salt, white and crystalline, with excellent buffering and fluxing properties. Available in powder or granular form, Borax Decahydrate is an important multifunctional source of B2O3, particularly for processes in which the simultaneous presence of sodium is beneficial.