Feeling their way underground: (left) Examining fluorite veins at KHD Fluorite’s Maly deposit, Khentii, eastern Mongolia, about to start production (courtesy KHD); (right) mining in the Käfersteige mine, Pforzheim, south-west Germany, prior to its closure in 1996. Deutsche Flussspat are looking to bring it back into operation by 2030 (courtesy Geological State Office of Baden-Württemberg); (inset) Planned Li-ion battery manufacturing for EV in Europe has sparked interest in developing regional sources of fluorspar (courtesy EDF).