The discovery of rare earths started in 1787 when Swedish Army Lieutenant Karl Axel Arrhenius collected the black mineral ytterbite (laterrenamed gadolinite) from a feldspar and quartz mine near the village of Ytterby, Sweden (Weeks and Leicester, 1968, p. 667). Although rare-earth bearing minerals were collected prior to this time, none were identified ascontaining a new "rare" and different "earth" (a historical term for an oxide) until B.R. Geijer of the Royal Mint of Sweden, forwarded the Arrhenius sample to Finland for analysis.
Separation of the first impure rare-earth oxide from ytterbite occurred in 1794 when Finnish chemist Johann Gadolin (University of Abo) made an impure yttrium marking the beginning of a scientific saga that was to extend over a century and a half to separate, identify, and produce pure compounds and metals. In 1797, in honor of Johann Gadolin’s discovery, A.G. Ekeberg of Uppsala, Finland, proposed the name gadolinite for the mineral and yttria for the "new earth" (Kaczmarek, Jean, 1980).    /...4