Yttrium was first identified in 1794 by the Finnish chemist Johan Gadolin, in a black mineral from a quarry at Ytterby, near Stockholm. That single quarry proved extraordinarily rich in rare-earth elements, and yttrium was the first drawn from it. It is a silvery transition metal, used in phosphors, lasers, and high-temperature superconductors. Yttrium provides the red phosphors of older colour screens and the phosphors of white LEDs, forms the strong garnet crystals used in lasers and microwave devices, and is a component of some high-temperature superconductors and heat-resistant ceramics. The mineral Gadolin studied at Ytterby was itself later renamed gadolinite in his honour, a rare case of a mineral being named after the person who first analysed it rather than the reverse.
Yttrium aluminium garnet, YAG, doped with neodymium, forms the crystal at the heart of the Nd:YAG laser, one of the most widely used solid-state lasers in industry and medicine, applied in everything from metal cutting and engraving to eye surgery and tattoo removal, so a metal identified from an obscure Swedish quarry now sits inside instruments used on operating tables around the world. Gadolin himself trained under the Swedish chemist Torbern Bergman and was one of the first scientists in his country to teach chemistry along the new Lavoisian lines, making his identification of yttrium as much a marker of a changing science as of a single new element.