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
Minette (ore) low iron content, however, meant that Lotharingian Minette-ore was successively replaced by more highly concentrated imported ores (with iron contents around 60%). As a consequence, more and more mins were closed down. The last pit in Luxembourg, Differdange, closed in 1981, the last French one, at Audun-le-Tiche in the Moselle department did so in 1997. Minette (ore) Minette is a type of mineral deposit, consisting of iron ore of sedimentary origin, found in the south of Luxembourg and in Lorraine. Minette ore was deposited in the Early Jurassic and Middle Jurassic. The term "Minette" came from French miners. It is