What is the chemical formula of the mineral used by the inventor known as 'The Wizard of Menlo Park' in 1895?
Scheelite Scheelite is a calcium tungstate mineral with the chemical formula CaWO. It is an important ore of tungsten (wolfram). Well-formed crystals are sought by collectors and are occasionally fashioned into gemstones when suitably free of flaws. Scheelite has been synthesized using the Czochralski process; the material produced may be used to imitate diamond, as a scintillator, or as a solid-state lasing medium. It was also used in radium paint in the same fashion as was zinc sulphide, and Thomas Edison invented a fluoroscope with a calcium tungstate-coated screen, making the images six times brighter that those with barium platinocyanide; the latter chemical allowed Röntgen to discover X-rays in early November 1895.
Hercynite Hercynite is a spinel mineral with the formula FeAlO.