Rare earths containing end-product materials for commercial use or for research applications are numerous. A complete description of the most popular among these materials was given in the section on applications of rare earths in Chapter 1. These materials can be basically divided into two groups. One group comprises commercially used rare-earth compounds, alloys, and metals, while the other group comprises rare earth-bearing products obtained using rare-earth compounds, alloys, and metals as the interprocess intermediates. This chapter focuses on the preparation of the commercially used rare-earth compounds, alloys, and metals. Several materials, for example, rare-earth compounds such as the chloride, hydroxide, fluoride, oxide, and carbonates, figure as intermediates obtained during routine ore processing or by processes branched readily from the regular flow sheet. The preparation of these compounds was therefore included in the chapter on resource processing. Preparation of elemental rare earths was covered in the preceding two chapters, which also included certain references to the preparation of rare-earth alloys, either because the processes used were very similar or because the alloys were interprocess intermediates for the preparation of pure metals.