Cerium

Cerium was named for the asteroid Ceres, which was discovered in 1801. The element wasdiscovered two years later in 1803 by Klaproth and by Berzelius and Hisinger. In 1875Hillebrand and Norton prepared the metal.

Cerium is the most abundant so-called rare-earths metal. It is found in a number ofminerals including allanite (also known as orthite), monazite, bastnasite, certie, andsamarskite. Monazite and bastnasite are presently the two more important sources ofcerium.

Large deposits of monazite (found on the beaches of Travancore, India and in riversands in Brazil), allanite (in the western United States), and bastnasite (in SouthernCalifornia) will supply cerium, thorium, and theother rare-earth metals for many years to come.

Metallic cerium is prepared by metallothermic reduction techniques, such as reducingcerous fluoride with calcium, or using electrolysis of molten cerous chloride or others processes. The metallothermictechnique produces high-purity cerium.