Classification of the Diamond according to the 4 criteria The Diamond: The Rule of 4C The diamond is classified according to the rule of 4C: Carat, Clarity, Color, Cut (International Standards). The color (from D for the best color to M-Z) Purity (from IF for the best purity to P3 for the least desirable) Size … Continue reading Diamond Grade | Carat, Clarity, Color and Cut