Spanish chemist and mineralogist who in partnership with his brother Juan José was the first to isolate tungsten, or wolfram (1783), though not the first to recognize its elemental nature. After teaching at Vergara, in Spain (1781–85), Fausto accompanied his brother to several European colleges, including the Freiberg (Saxony) School of Mining and the University of Uppsala in Sweden. In 1788 he was appointed supervisor of the Mexican mining industry; his work was ended by the revolutionary movement early in the 19th century. On his return to Spain he was named director general of mines and minister of state. He wrote several volumes on mineralogy and coining.