So many new and exciting topics in petrology have appeared over the last several years that it has become difficult to find a text that deals adequately with fundamentals as well as current topics; the present book may be one of the better texts in its field today because it achieves this combination with clarity and appropriate emphasis. The book provides a comprehensive coverage of descriptive, theoretical, and experimental topics. The relationship between the origin and evolution of igneous and metamorphic rocks and the associated physical and tectonic processes is the unifying theme of the text.The book is intended as a text for undergraduate geology majors with a background in physical and historical geology and mineralogy. It is divided into four main categories: magmatic rock bodies, magmatic systems, metamorphic bodies and systems, and the early history of the earth and other planetary bodies. The organization of the first three of these sections is intended to be flexible in scope, emphasis, and variety of subject matter. Each chapter is outlined, prefaced with an overview of the section, and summarized in outline form. Key terms appear in bold type, and study questions are provided in interpretive chapters. Breadth and clarity of subject matter is emphasized, and good use is made of figures, tables, and photographs of rocks in the field, in hand specimen, and in thin section. The appendix contains a summary of some petrographic techniques, a review of the physical and optical properties of some rock‐forming minerals, and representative chemical analyses of some major rock types.