It is important to mention that oxides of rare earth elements (REEs) are found in raw condition and require processing based on grain size, growth, and characteristics. Prioritization is based on different refining techniques and potential applications of the oxides. Rare earth materials or elements have limited applications and therefore require processing that involves several steps, which can be time consuming and costly. Preliminary studies performed by the author revealed that the prices per pound for the heavy rare earth elements (HREEs) are higher than those of their oxides. The studies further revealed that the prices of the light rare earth elements (LREEs) are much lower for lanthanum (La), cerium (Ce), praseodymium (Pr), and neodymium (Nd) because of low processing costs. The studies indicate that costs for REEs such as thulium (Tu) and europium (Eu) are relatively high due to their wide commercial and industrial applications. All rare earth elements, including the LREEs, are shown in Figure 2.1.