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
Mineral resource classification Mineral resource classification Mineral resource classification is the classification of mineral resources based on an increasing level of geological knowledge and confidence. Mineral deposits can be classified as: In common mining terminology , an "ore deposit" by definition must have an 'ore reserve', and may or may not have additional 'resources'. Classification, because it is an economic function, is governed by statutes, regulations and industry best practice norms. There are several classification schemes worldwide, however the Canadian CIM classification (see NI 43-101), the Australian Joint Ore Reserves Committee Code (JORC Code), the South African Code for the Reporting of Mineral