The methodological manual summarizes the basic information on crystal optics necessary for mastering the microscopic method of studying rocks. Described the device of the polarizing microscope and rules for working with it. Methods and techniques of research of rock-forming minerals and determination of their most important diagnostic constants are considered. Recommendations for the study and description of rocks in the cliffs. The manual is intended for graduate students, masters, students of the geological faculty of full-time and part-time education, can be used in the independent study of magmatic, metamorphic and sedimentary rocks.