Question: What is the chemical formula of the mineral used by the inventor known as 'The Wizard of Menlo Park' in 1895?
Sentence (from "Scheelite"): 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.
Relevant evidence: Yes