Rare earth elements are a set of 17 chemical elements in the periodic table, specifically 15 lanthanides (lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium) as well as scandium and yttrium.
Les terres rares regroupent 17 éléments chimiques classés dans le tableau périodique, dont 15 lanthanides (lanthane, cérium, praséodyme, néodyme, prométhium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium et lutétium), ainsi que le scandium et l’yttrium.