Other forms: boraxes
Borax is a mineral that's often used in a powdered form as a cleanser or water softener.
Borax is another name for sodium borate, a chemical salt that was discovered in 8th-century Tibet. Medieval ceramicists used borax in their pottery glazes, and in modern times it's been used to make glass. Borax can also act as a fire retardant in wood and textiles. In household use, borax is still sometimes added to a load of laundry or worked into soil as a fertilizer. It is widely attested that the name borax comes from the Persian word būrah.