Geography of Illinois before the dinosaurs. Galena, a lead ore, has been mined in the northwest corner of the state. The ore was processed around Peru, Illinois, where river transport was available to bring the ore to a source of coal. About six tons of coal are needed for each ton of ore. Fluorite, calcium fluoride, is the state mineral. It is mined in the southeastern portion of the state, around Metropolis. Fluorine gas is produced from fluorite. This is used in the production of uranium hexafluoride in Metropolis, Illinois for use at the gaseous diffusion plant in Paducah, Kentucky. Geodes can be
Silver Valley (Idaho) Lewis and Clark line – a series of strike-slip faults running across the Pacific Northwest – crosses this anticline, generally trending in an east-west direction. Within this mining district, the major structure of the lineament is the Osburn fault, which runs directly through the district’s most successful silver belts. Its 16-mile (27 km) displacement divides the district into two distinct parts, the southern Page Galena Belt, and the northern Golconda Lucky Friday Belt. Three main minerals make up most of the ore production in the Silver Valley. Galena (PbS or lead(II) sulfide) is the most important ore mineral found in