This manual of essentials for the setup and operation of a polarized light microscope for microscopic particle characterization and identification grew out of a need for Hooke College of Applied Sciences, a member of The McCrone Group, to have a modern textbook for use in their microscopy courses. This textbook provides an up-to-date, fresh approach to applied polarized light microscopy as required for diverse applications such as industrial problem solving, contaminant identification, bioterrorism and other hazardous material identification, trace evidence analysis, paint and pigment analysis, etc. The essentials described in this manual have a rich history going back hundreds of years and are a heritage still useful and applicable today, and for the forseeable future. In addition to its use in Hooke College classes, this edition will find use in other institutions of learning, and can be used for independent study. The microchemical tests have been greatly expanded with color images under several microscopical lighting conditions, added directions, notes, cautions, sensitivity of reactions, and a bibliography as to page and figure number to the reactions in books in English, German, French, and Russian.