The geochemistry of the eartha (TM)s surface is controlled by chemical equilibrium, and the kinetics of the approach toward equilibrium. Many low temperature processes, such as weathering, do not reach equilibrium except over geologically long time periods. The approach to equilibrium can be described by kinetic theory and the application of kinetic theory to geochemical systems has made vast advances in the last several decades. Geochemical kinetics as a topic is now of importance to a wide range of geochemists in academia, industry, and government, and all geochemists need a rudimentary knowledge of the field. This book will summarize the fundamentals of geochemical kinetics with examples drawn especially from mineral dissolution and precipitation, but will also encompass discussion of high temperature processes and global geochemical cycle modeling. Analysis of textures of rocks, sediments, and mineral surfaces will be incorporated throughout and will be a subtheme of the book.