Borax - Na₂B₄O₅(OH)₄ · 8H₂O

Habit: Colorless, grey, white or yellowish; seldom bluish or greenish. Crystals commonly short prismatic, often tabular and striated, often malformed by abnormal development of part of one or more zones. Vitreous to resinous luster, but may be earthy; translucent to opaque. White streak.

Environment: Occurs in evaporite deposits, salt lakes and playas, usually well crystallized; also found as efflorescence on soils in arid regions.

Etymology: From the Arabic bauraq, meaning "white."

Borax has a wide variety of uses, including as a component of many detergents, as an insecticide and in cosmetics.