Georges Urbain

…Carl Auer von Welsbach and Georges Urbain, working independently. Urbain derived the name for the element from Lutetia, the ancient Roman name for Paris, to honour his native city. The name lutetium became widely accepted except in Germany, where it was commonly called cassiopeium until the 1950s. One of the…

…other heavy lanthanides; French chemist Georges Urbain later (1906) was able to prepare a reasonably pure fraction. Some important mineral sources of dysprosium are laterite ionic clays, xenotime, fergusonite, gadolinite, euxenite, polycrase, and blomstrandine. It also occurs in the products of nuclear fission.

French chemist Georges Urbain and Austrian chemist Carl Auer von Welsbach independently demonstrated in 1907–08 that Marignac’s earth was composed of two oxides, which Urbain called neoytterbia and lutetia. The elements are now known as ytterbium and lutetium. Ytterbium is among the less-abundant rare earths. It occurs…