This book has been compiled to be like no other rock identification guide ever published. Almost 750 images are used to tell the story about how rocks formed and how to identify them using mostly observational methods. This book features or describes 43 of the most common igneous, sedimentary, and metamorphic rocks and associated minerals. Although some of the featured varieties and geologic background information pertaining to the Lake Superior region, the identification tips are relevant to rocks found worldwide. Photographs of specimens or geologic information are included from 35 American states and 18 other countries.