Gallium Silicotungstate

Gallium silicotungstate is very soluble in water. Three hydrates are known: the first, which has the formula 2Ga₂O₃.3(SiO₂.12WO₃).93H₂O, crystallises in regular octahedra; the second has 87H₂O and crystallises in rhombohedra (a:c = 1:2.6346); while the third has 60H₂O and crystallises in the monoclinic (?) system (a:b:c = 0.9057:1:1.1585; β = 74°20'). The first two salts therefore correspond to those of aluminium.