Polarizing Microscope is another type of compound microscope. which can enhance the contrast and image quality on specimen where other techniques such as phase contrast or darkfield are not as effective. Two polarizing filters are used called the 'polarizer' and 'analyzer' filters. The polarizer is placed in the path of the light source, and the analyzer in the optical pathway. Polarizing compound microscopes are used to examine chemicals in the pharmaceutical industry and petrologists and geologists use polarizing microscopes to examine minerals and thin slices of rocks.