Rare earth

Rare earth, name for the elements scandium and yttrium and the lanthanide series, Group IIIB of the Periodic Table, occurring throughout nature as monazite and other ores. They are separated by chromatography and ion-exchange resins. Rare earths are used in alloys, including misch metal, and their compounds (mixed or separately) are used as abrasives, for making glasses and ceramics, as “getters,” as catalysts in the petroleum industry, and to make phosphors, lasers, and microwave devices.

See also: Berzelius, Jöns Jakob, Baron.