Tungstate

[2] Orthotungstates feature tetrahedral W(VI) centres with short W–O distances of 1.79 Å.

Scheelite, the mineral calcium tungstate, often contains a small amount of molybdate.

Wolframite is manganese and iron tungstate, and all these are valuable sources of tungsten.

Powellite is a mineral form of calcium molybdate containing a small amount of tungstate.

Solutions of tungstates, like those of molybdates, give intensely blue solutions of complex tungstate(V,VI) analogous to the molybdenum blues when reduced by most organic materials.

Chemical structure of the orthotungstate ion ( WO 2− 4 )