the optical properties of diamonds are (a) adamantine luster depends on high polish and quality of light, (b) the ability of a well-cut diamond to totally return back a ray of light, which enters from the crown, and (c) the optical effect fire exhibited by the stone due to breaking up of white light into rainbow spectrum color. Fire is known as dispersion. Fire or dispersion caused by differing refracting indexes of each different color rays, which all together form the white light, for example, the red color has a wavelength of 687 nm and a refractive index of 2.407 in diamond, and violet ray has a wavelength of 397 nm and a refractive index of 2.465, correspondent to B line for red ray and G line for violet ray of Fraunhofer’s solar spectrum diamond has a (d) dispersion of 0.044.