Rock hounds from amateur to science teacher are sure to be interested in this comprehensive reference on the state’s rocks and minerals. More than 40 color plates display excellent examples of rock types ranging from fluorite (the state mineral) to the world-renowned geodes of western Illinois. The photographs are accompanied by detailed descriptions of both common and very unusual rocks and minerals in Illinois. Useful identification flow charts and keys help the reader identify their specimens. In addition, the guide summarizes the basic geology of Illinois and discusses the physical properties of rocks and minerals, ways to collect and identify samples, and the importance of rocks and minerals to society.