The Ideal Cut diamond has been correctly cut and the light entering the diamond will return to the eye. The deep cut diamond has been cut too narrow and deep and again looses the light out the pavilion. Diamonds are cut by the manufactures to yield the greatest amount of carat weight from the rough, which they also buy by the carat. It is a totally colorless diamond that allows white light to pass effortlessly through it and be dispersed as rainbows of color. Color grading scale from totally colorless to light yellow.
Most diamonds contain very tiny birthmarks known as inclusions.
However, the fewer and smaller the inclusions are, the more beautiful the diamond will be. Diamonds, more than any other gemstone, have the capability to produce the maximum amount of brilliance. A diamond that is free of both inclusions and surface blemishes is very rare and therefore very valuable. This is the weight of the diamond measured in carats. Carat-weight is the easiest of the 4C's to determine.