Mother Nature may determine a diamond's color, clarity, and carat-weight, but the hand of a master craftsman is needed to release its fire and beauty. The right cut gives each diamond unique sparkle and brilliance by allowing the maximum amount of light to enter and reflect back out of the diamond. If the cut is too deep or shallow, light will spill through the side or bottom and be lost, resulting in a less brilliant display and a less valuable diamond. A well-cut diamond is considerably more beautiful and valuable than a poorly cut stone of the same size, clarity, and color. Color - The best color is no color.
Color is judged according to a grading scale.
Diamond color grades start at D and continue through the alphabet all the way to Z. Colorless diamonds are the most valued because they are the most rare. Differences between one color grade and another are very subtle, particularly to the untrained eye. Although increasing shades of yellow reduce the value of a diamond, they do not necessarily reduce its beauty. If a diamond is well cut, its refraction and dispersion of light will often disguise certain degrees of coloration. Clarity - It's a rarity.