This book highlights major problems in the statistical analysis of compositions that have been known for over a century, as well as the corresponding solutions that have been put forward by specialists over the past 30 years. The basic assumptions of normality or multi-normality are pointed out and methods to test and achieve them are also covered. The conventional major and trace element geochemistry and modeling equations are discussed, and are followed by a more sophisticated multidimensional approach to data handling. The book’s main focus is on the use of statistical techniques to facilitate data interpretation. It also highlights the classification (or nomenclature) and tectonic discrimination aspects for both igneous and sedimentary rocks. The book concludes by discussing computer programs that are helping pave the way from geochemistry to geochemometrics. Written by a leading expert in the area of geochemistry, it offers a valuable guide for students and professionals in the area.