Book excerpt: This book is a brief summary of the course of lectures in Geochemistry for undergraduate and graduate students from other than Geological Departments (chemists, biologists, ecologists and naturalists). It describes the Earth’s structure and some geological processes. The modern geochemical concepts take proper account of global geological processes and the influence of Cosmos. They are based on the laws and approaches of equilibrium and non-equilibrium thermodynamics. The cycles of energy and chemical elements within the Earth are interrelated with the global geochemical cycle. In addition to the traditional Geochemistry course, this book offers Geochemistry of microorganisms, Geochemistry of dispersed systems, Geochemistry of cryogenesis, and Geochemistry of cryptobiosphere. Features: Provides the reader with a general idea of the Earth’s chemical life and its related global geological events Offers a concise and clear description of the modern concepts in Geochemistry, including new directions such as Geochemistry of Cryogenesis, Geochemistry of Disperse Systems, Geochemistry of Microorganisms, and Geochemistry of Cryptobiosphere Implies a wide application of the thermodynamic approach. Useful for students who, though lacking in geology basics, are experienced in chemistry and biology