Rare earth materials are often characterized by various names, such as rare earth elements (REEs), rare earth metals (REMs), rare earth oxides, or yttriumbased rare earth material. Essentially, rare earth materials are classified into two distinct categories: light rare earth elements (LREEs), which is known as the cerium group, involving lanthanum-europium, and heavy rare earth elements (HREEs), also known as the yttrium group, consisting of gadolinium-lutetiumyttrium elements. Based on pertinent scientific papers, published reports, and chemical elements, REMs (or REEs) are composed of a set of 17 chemical elements as listed in the periodic table . Furthermore, the 17 rare earth materials include 15 lanthanides plus scandium and yttrium. Scandium and yttrium are considered to be rare earth elements because they tend to occur in the same core deposits as lanthanides and exhibit identical chemical properties.