Volume 23 of Reviews in Mineralogy and accompanying MSA short course covers chemical reactions that take place at mineral-water interfaces. We believe that this book describes most of the important concepts and contributions that have driven mineral-water interface geochemistry to its present state. We begin in Chapter 1 with examples of the global importance of mineral-water interface reactions and a brief review of the contents of the entire book. Thereafter, we have divided the book into four sections, including atomistic approaches (Chapters 2- 3), adsorption (Chapters 4-8), precipitation and dissolution (Chapters 9-11), and oxidation-reduction reactions (Chapters 11-14).