The word “tungsten” is an adaptation of the Swedish tung sten (heavy stone) and was first applied to the mineral scheelite about 1758. The element was first identified in 1781 by a Swedish chemist, K.W. Scheele, for whom the calcium tungstate mineral, scheelite, was later named. Commercially, tungsten is prepared from scheelite.
Further processing results in a yellow powder of tungsten tri-oxides that would be considered extremely pure by most commercial standards. However, the desired properties of tungsten wire are affected so adversely by minute quantities of unwanted impurities that another purification is added. This consists of re-dissolving the hydroxide, purifying the solution, and crystallizing the tungsten out in the form of ammonium paratungstate.