Element Cerium, Ce, Lanthanide

Ceria earth was discovered by Martin Heinrich Klaproth in Germany and Berzelius with Hisinger in Sweden, and independently in 1803. Long before that Cronstedt was investigating a specimen of a new mineral found in Bastnas mine. In 1803 another specimen of the new earth oxide, a brown powder was sent to Klaproth. At the same time Berzelius also analyzed the new mineral and both, Berzelius and Hisinger, were intrigued by the mysterious "heavy spar" which they at first took as a sort of gadolinite which was supposed to contain copper, bismuth and molybdenum sulphur compound. After scrupulous operations they managed to extract oxide of some new metal, as much as 50% of the entire mineral weight. Cerium was so named by Berzelius after the dwarf planet Ceres, discovered in 1801.

Lanthanide cerium crustal abundance is 7x10^-3 mass %, in seawater 1.3x10^-6 mg/L. Cerium can be found mostly in light lanthanides; for this reason the whole subgroup is called ceric subgroup of the lanthanides. Cerium accompanies rare earth elements in monazite, bastnasite, apatite etc. Cerium concentrations in these minerals vary between 25 and 55% of total rare earth elements amount.