vauxite

{{Infobox mineral | name = Vauxite | category = Phosphate minerals | boxwidth = 24 | boxbgcolor = crystally blue | image = Vauxite-Paravauxite-240628.jpg | imagesize = 260px | caption = Vauxite from the Siglio XX Mine, Llallagua, Bolivia. Specimen size 2 cm | formula = Fe2+Al2(PO4)2(OH)2.6H2O | IMAsymbol = Vx | molweight = 441.86 g/mol | strunz = 8.DC.35 | dana = 42.11.14.1 | color = Blue, becoming greenish on exposure | habit = Minute tabular crystals, radial aggregates and nodules | system = Triclinic | class = Pinacoidal () (same H-M symbol) | symmetry = P | twinning = On {010}, twin and composition plane. | cleavage = Fractured | mohs = 3.5 | luster = Vitreous | refractive = Nx=1.551, Ny=1.555, Nz=1.562 | opticalprop = Biaxial (+) | birefringence = r>v | pleochroism = (strong): X, Z colorless, Y blue | streak = White | gravity = 2.39 to 2.40 | density = | melt = | fusibility = | diagnostic = | solubility = | diaphaneity = Transparent to translucent | other = Fluorescent. Not radioactive | references = }}

Vauxite is a phosphate mineral with the chemical formula Fe2+Al2(PO4)2(OH)2·6(H2O). It belongs to the laueite – paravauxite group, paravauxite subgroup, although Mindat puts it as a member of the vantasselite Al4(PO4)3(OH)3·9H2O group. There is no similarity in structure between vauxite and paravauxite Fe2+Al2(PO4)2(OH)2·8H2O or metavauxite Fe3+Al2(PO4)2(OH)2·8H2O, even though they are closely similar chemically and all minerals occur together as secondary minerals. Vauxite was named in 1922 for George Vaux Junior (1863–1927), an American attorney and mineral collector.