rare earths

"Rare earths" refers to a group of 17 chemically similar metallic elements that include the fifteen lanthanides on the periodic table, plus scandium and yttrium. These elements are used in many high-tech applications—such as magnets, batteries, and electronic devices—because of their special magnetic, luminescent, and electrochemical properties. Despite the name, most rare earths are relatively abundant in the Earth’s crust but are rarely found in economically extractable concentrations.