A mineral, (chemical formula Na2B4O7.4H2O) which when mixed with clay, forms vast deposits in California, similarly to colemanite which often forms large, multifaced crystals.

Its main deposits are Death Valley in California (USA) and Panderma in Turkey. Its compounds are used mainly in medicine and chemical industry, in the manufacture of soap and glass, in melting porcelain mass and in the manufacture of modern washing and leaching preparations. Its alloys are used for regulation bars in nuclear reactors and for protection against neutron radiation.