Magnesium Tungstates

Large, colourless, octahedral and columnar crystals of MgWO₄ are obtained by fusing sodium tungstate with excess of magnesium chloride and salt. Ullik obtained a heptahydrate by acting on magnesium carbonate with tungstic acid. The metatungstate, MgO.4WO₃.8H₂O, and the paratungstate, 3MgO.7WO₃.24H₂O, have been prepared. Various double tungstates have also been reported.