This is a wonderful free resource for Illinois rock lovers! You can go to the Illinois State Geological Survey site and download every chapter.
The book starts by stating: “At first glance, Illinois, “The Prairie State,” may appear to be an unlikely place in which to collect rock and mineral specimens. But Illinois is surprisingly rich in rock and mineral resources, thanks to the great diversity and wealth of materials beneath its land surface. The state contains some of the most interesting mineral and rock specimens in the world.”