Bauxite is a naturally occurring, heterogeneous material composed primarily of one or more aluminum hydroxide minerals, plus various mixtures of silica, iron oxide, titania, aluminum silicates, and other impurities in minor or trace amounts. Bauxite is called as a ore produced by residual weathering or in situ chemical weathering typically under tropical to subtropical climatic conditions. The principal aluminum hydroxide minerals found in varying proportions with bauxites are gibbsite and the polymorphs boehmite and diaspore. Bauxites are typically classified according to their intended commercial application: abrasive, cement, chemical, metallurgical, refractory, etc.The bulk of world bauxite production (approximately 85%) is processed into aluminum oxide (Al2O3, also known as alumina) via a wet chemical, caustic leach method.