The primary aim of this monograph is to present the current knowledge of brittle properties of rocks as determined in laboratory experiments. The principal aspects of brittle behavior are described with special attention to the fundamental physical aspects. Thus, the book provides a useful introduction to the basics of rock properties for engineering and earth science applications. Furthermore, it serves as a guide for graduate students and non specialists by presenting the relevant background material and where it can be found. For the new edition a further chapter has been added, and almost half of the chapters have been extensively revised and the others updated.