Spain is the most self-sufficient country for minerals in the EU. A major proportion of these Spanish mineral resources has been obtained from Tertiary materials. The main materials exploited in Tertiary basins have been: brown coal and lignites, potassium salts, sodium salts (sulphates and chlorides), diatomite, sepiolite and other absorbent clays, bentonites, celestine, pumice, and also dimension (building-) stones and ceramics, portland cement and plaster raw materials.
Pb–Zn–Ag and gold alunite volcanogenic ores, related to Neogene volcanism, besides Au-placers have been mined from Roman times. Minor Cu and Mn occurrences are also reviewed.
The brown coal mines of Galician basins have provided all the significant production of Spain: more than 17 Mt. Low-quality Oligocene lignites in the eastern part of the Ebro Basin and Balearic Islands are less important from the economic point of view. Other occurrences are in the Guinzo de Limia, Guadix Baza, Granada (Arenas del Rey) and Alcoy basins.
The Spanish Tertiary basins (continental and marine) (Oligocene–Miocene) are filled by thick evaporites in which are obtained potassium salts and sodium salts (sulphates and chlorides). The Montevives celestine mine is located in the evaporitic unit of the Granada basin (Miocene), and provides all of the Spanish celestine production. Spain is the world's third largest producer of celestine.
The Madrid basin and the minor Calatayud basin supply the whole of Spanish sepiolite production. The most important Spanish attapulgite production is obtained from the El Cuervo mine (Sevilla and Cádiz provinces).