Polarized light microscopy provides all the benefits of bright field microscopy and yet offers a wealth of information, which is simply not available with any other optical microscopy technique. Providing information on absorption color and boundaries between minerals of differing refractive indices obtainable in bright field microscopy, polarized light microscopy can distinguish between isotropic and anisotropic materials. The technique exploits optical properties of anisotropy to reveal detailed information concerning the structures and composition of materials, which are invaluable for identification and diagnostic purposes. Isotropic materials demonstrate the same optical properties in all directions. They only have one refractive index and no restriction on the vibration direction of light passing through them. Anisotropic materials have optical properties that vary with the orientation of incident light with the crystallographic axes. They illustrate a variety of refractive indices depending both on the propagation direction of light through the substance and on the vibration plane coordinates. Anisotropic materials act as beam splitters and divide light rays into two parts. The technique of polarizing microscopy exploits the interference of the split light rays, as they are re-united along the same optical path to extract information about these materials. Polarized light microscopy is best known for its geological applications and it’s primarily for the study of minerals in rock thin sections, but it can also be used to study many other materials. The technique can be used both qualitatively and quantitatively and is an outstanding tool for materials science, geology, chemistry, biology, metallurgy and even medicine. Understanding of the analytical technique of polarized microscopy is perhaps more demanding than other forms of microscopy, simply for the enhanced information that can be obtained over bright field imaging. An awareness of the principles of polarizing microscopy is as well essential for the effective interpretation of differential interference contrast microscopy. The wave model of light describes light waves vibrating at right angles to the direction of travel of light with all vibration directions being equally probable which common light is. The human eye-brain system has no sensitivity to the vibration directions of light and plane-polarized light can just be detected by an intensity or color effect. Land invents Polaroid film in 1932 and it consists of long polymers, treated with light absorbing dyes and stretched so that the chains are aligned. Light vibrating parallel with the chains is absorbed while light perpendicular to the chains is transmitted. The two polarizing filters in a polarizing microscope are the polarizer and analyzer.