Synopsis The first chapters of this textbook cover basic principles of geochemical applications to Natural waters and deep Earth and plan-etary processes. The book introduces Topics rarely covered in a single text and emphasizes processes over descriptive material. Suitable for an Introductory class, the textbook can also be used as a quick Review of geochemical concepts by scientists from other fields. In summer, this is an effective entry-level text that deserves to be widely read. This is a benchmark book in its field. Its forthright numerical approach is refreshing and important. Readers will not need to know Advanced Mathematics to understand the book. This book is a valuable source of information for the non-specialists eager to Learn geo-chemistry.