Scientific and technological research involving RARE EARTH ELEMENTS (REEs) can be considered a matter of national strategy. They are present in our daily lives in permanent magnets, light bulbs, computer chips, monitors, glass colourants, X-ray machines, as contrasting agents in clinical examinations, in high-resolution lenses, among others. Furthermore, it is believed that a country that has knowledge and/or scientific-technological mastery of these elements can be considered a very important country on the world economic stage. Specifically, this book comes from a project funded by the National Research Council - MCT (CNPq 405806/2013-2). It is characterised as interdisciplinary, as it involves human resources from the fields of engineering, natural and exact sciences and health. This book is considered part 1 of this major project, while part 2 deals with more specific examples in the field of geology, geophysics and geostatistics developed in the central region of the state of Rio Grande do Sul, southern Brazil. Generally speaking, this project aims to approach ETR from a geological, geophysical, chemical and pharmaceutical perspective.