Susanne Theodora Schmidt was educated at the University of Heidelberg (Germany) and the University of Minnesota, Duluth (USA). With her students and collaborators, she has conducted research projects on metamorphic petrology in low-grade and high-grade metamorphic terranes in North and South America and Europe. She also applied her mineralogical insight to a variety of other topics including gemology and health- and environmental-related issues. She has taught metamorphic petrology, mineralogy, and optical mineralogy at the Universities of Heidelberg (Germany), Basel (Switzerland), and Geneva (Switzerland). The present book reflects her experience of teaching optical mineralogy to many generations of students in Earth Sciences in the most efficient way possible.