Earth metals is a term used to describe 17 chemical elements in the periodic table of the elements: scandium, yttrium, and the 15 lanthanides. The so-called rare earth elements are used in many technological devices. 

Here's the full list of the rare earth metals, preceded by their symbols: La lanthanum, Tb terbium, Ce cerium, Dy dysprosium, Pr praseodymium, Ho holmium, Nd neodymium, Er erbium, Pm promethium, Tm thulium, Sc scandium, Sm samarium, Yb ytterbium, Eu europium, Lu lutetium, Gd gadolinium, and Y yttrium. 

Certain of the rare earths are used to manufacture high performance permanent magnets used in electric motors and generators. Hence, they are considered essential for some businesses like wind turbines.