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
Galena, Illinois Galena, Illinois Galena is the largest city in and the county seat of Jo Daviess County, Illinois, with a population of 3,429 at the 2010 census. A section of the city is listed on the National Register of Historic Places as the Galena Historic District. The city is named for the mineral galena, which was mined by Native Americans in the area for over a thousand years. Owing to these deposits, Galena was the site of the first major mineral rush in the United States. By 1828, the population was estimated at 10,000, rivaling the population of Chicago at the