Another new earth, from the mineral later named gadolinite in Gadolin's honor, is reported independently in the literature in 1803 by several chemists, including Martin Heinrich Klaproth and, working together, Jöns Jakob Berzelius, and Wilhelm Hisinger.
The asteroid Ceres, which had just been discovered two years before, lends its name, as ceria, to the newly obtained earth.
Researchers refer to yttria and ceria as the rare earths, because they have been discovered in a rare mineral, and closely resemble other known earths.
The elements of which yttria and ceria were the oxides then receive the names yttrium and cerium, respectively.
