A review of the garnet-rich volcanic Complex of El Hoyazo (SE Spain) is given, including new data about the petrology and geochemistry of the volcanic area, and suggesting a methodological proposal for evaluating the use of garnets as a guide to mineral deposit exploration. This is significant as the Neogene volcanic region of SE Spain hosts a wide variety of mineral deposits making up a metallogenetic belt from Cartagena to Cabo de Cata: Pb-Zn (± Ag,Sb) (Mazarron, Sierra Almagrera), Sb-Hg-Ba (±Au) (Valle del Azogue), Fe-Mn-Ba-Ag (Las Herrerías), native Au (Rodalquilar). The current exploitation of the garnets as industrial raw material is also described