What is Bauxite?
[[Image:Bauxite with unweathered rock core. C 021.jpg|thumb|Bauxite with core of unweathered parent rock]] [[File:140606 Les-Baux-12.jpg|thumb|Bauxite in [[France]]]] '''Bauxite''' is the main [[ore]] of [[aluminium]]. It is mostly [[aluminium oxide]]. Bauxite is the most important aluminium ore. It is largely made up of the [[mineral]]s Gibbsite Al(OH)<sub>3</sub>, Boehmite γ-AlO(OH), and Diaspore α-AlO(OH), together with the [[iron]] oxides [[Goethite]] and [[Hematite]], the clay mineral [[Kaolinite]] and small amounts of Anatase TiO<sub>2</sub>. It was named after the village Les Baux-de-Provence in southern [[France]], where it was first discovered in [[1821]] by [[geologist]] [[Pierre Berthier]]. Today the four biggest producers are [[Australia]], [[Brazil]], [[China]] and [[India]]. == Kinds == There are two main kinds of bauxite ores: [[carbonate]] bauxites (karst bauxites), and [[silicate]] bauxites (lateritic bauxites). Carbonate bauxites were discovered earlier, and occur mainly in Europe and Jamaica above carbonate rocks such as [[limestone]] and [[dolomite]]. Lateritic bauxites occur in many countries of the [[tropical]] belt. They were formed from various [[silicate]] rocks such as [[granite]], [[gneiss]], [[basalt]], [[syenite]], and [[shale]]. For bauxite to be created there must be intense [[weathering]] conditions and very good [[drainage]]. Bauxite deposits with highest aluminium content are frequently located below an [[iron]]-bearing surface layer. In lateritic bauxite, the [[aluminum hydroxide]] contained in [[laterite]] deposits is almost entirely a form called [[gibbsite]]. [[Category:Rocks]] [[Category:Ores]]