an earthy, white borate mineral, hydrated calcium borate (Ca₄B₁₀O₁₉·7H₂O). It has been found as masses and nodules in a hot-spring deposit near Chetco, Ore., U.S.; as nodules in shale in Death Valley, Calif., U.S.; and as very large masses (weighing up to a ton) underlying gypsum and clay beds at Susurluk in northwestern Turkey. For detailed physical properties, see borate mineral (table).