Tungsten General Electric's attempt to patent it, overturning granted in 1913 to William D. Coolidge. Tungsten Tungsten, or wolfram, is a chemical element with symbol W and atomic number 74. The name "tungsten" comes from the former Swedish name for the tungstate mineral "scheelite", "tung sten" or "heavy stone". Tungsten is a rare metal found naturally on Earth almost exclusively combined with other elements in chemical compounds rather than alone. It was identified as a new element in 1781 and first isolated as a metal in 1783. Its important ores include wolframite and scheelite. The free element is remarkable for its
Melting point placed on a section of the strip, revealing its thermal behaviour at the temperature at that point. Differential scanning calorimetry gives information on melting point together with its enthalpy of fusion. A basic melting point apparatus for the analysis of crystalline solids consists of an oil bath with a transparent window (most basic design: a Thiele tube) and a simple magnifier. The several grains of a solid are placed in a thin glass tube and partially immersed in the oil bath. The oil bath is heated (and stirred) and with the aid of the magnifier (and external light source) melting