Book excerpt: Metallic resources play a huge role in many fields: in the energy transition, the development of new technologies and the production and storage of green energy. Metallic Resources 1 presents various studies in notable European metallogenic regions or deposits that enable us to tackle the question of the concentration of metals, especially strategic metals, in various geodynamic settings. An understanding of the geological processes that lead to the formation of deposits and influence their concentrations in the Earth's crust is of the utmost importance when it comes to uncovering new mineral resources. This book puts forward various different methodological approaches necessary in the study of deposits of metallic resources, from field observations to microanalysis. A study of specific geo-politico-economic frameworks is also presented.