Optical Mineralogy: Ordinary and polarized light, polarization of light, refractive index, critical angle and total internal reflection. Polarization by reflection, absorption, refraction. Double refraction, construction of Nicol prism. Isotropic and anisotropic substances. Petrological microscope- parts and functions. Optical accessories- mica plate, gypsum plate and quartz wedge. Birefringence, uniaxial and biaxial minerals, optic sign, relief, pleochroism, interference colour and its order, extinction. Basic description of indicatrix