The polarizing microscope is also known as the petrographic or petrological microscope. Polarizing microscope is the principal piece of equipment used by geologists and mineralogists to observe the optical properties of minerals. There are actually numerous microscopes available on the market today but petrographic polarizing microscopes are the most significant kind that is commonly used in optical mineralogy. Several microscopes vary considerably in their construction details. This applies particularly to the illumination and sub-stage condenser systems of the polarizing microscope. Some of these are designed for routine and uncritical work while others require adjustments to be made. It is therefore important to note that one must know how to correctly adjust these systems for the particular microscope being used.            In the ordinary kind of petrographic polarizing microscope, it is essentially ordinary kind but with the following important additional equipments namely, the polarizer, the analyzer and a rotating stage. A reflector is usually fitted with a plane mirror on one side, and a parabolic mirror on the other. The plane mirror should be used with sunlight, and the parabolic mirror with the artificial light, in order to make the rays of light as nearly parallel as possible.