. <br /><br />The three C's for giving diamonds as gifts are: cut, color, and clarity. Get a little help to try and understand these three 'C's. Cut is noted as the shape of the diamond and the terms will be princess, emerald, round, and so on. Color is the color of the diamond and they are rated from the letters D-X. The lower the letter in the alphabet, the better the color. So, the X range of diamonds is going to look on the yellow side. D is the whitest clearest color available, and consequently more expensive