In chemistry, paratungstate refers to the anion with the formula [W<sub>12</sub>O<sub>42</sub>]12- and salts derived from this anion. The term also refers to protonated derivatives of this anion, including [H<sub>2</sub>W<sub>12</sub>O<sub>42</sub>]10-. Ammonium paratungstate (or APT), (NH4)10[H<sub>2</sub>W<sub>12</sub>O<sub>42</sub>] is a key intermediate in the purification of tungsten from its ores.
The salt (NH4)10(W12O42)·4H2O has been characterized by X-ray crystallography.[1]
The unprotonated anion [W<sub>12</sub>O<sub>42</sub>]12- has C2h symmetry.