MineralogyMineral: sedimentary rock; high aluminium content. It is the world's main source of aluminium and gallium; dull in luster; reddish-brown, white, or tan.
Bauxite consists mostly of:Gibbsite (Al(OH)3).
Boehmite (γ-AlO(OH))
Diaspore (α-AlO(OH))
Plus
Goethite (FeO(OH))
Haematite (Fe2O3),
Kaolinite (Al2Si2O5(OH)4)
small amounts
Anatase (TiO2)
Ilmenite (FeTiO3 or FeO.TiO2).