Sodium tetraborate decahydrate (Na₂B₄O₇ ·10H₂O), a soft, light, colourless crystalline mineral used as a component of glass and pottery glazes in the ceramics industry, as a solvent for metal-oxide slags in metallurgy, as a flux in welding and soldering, and as a fertilizer additive, a soap supplement, a disinfectant, a mouthwash, and a water softener. About 50percnt of the world's supply comes from southern California deserts, including Death Valley.

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