How are diamonds color graded?
Color grading involves determining how little or much body color is in a diamond. The less body color, the higher the grade; the more body color, the lower the grade. This process has nothing to do with identifying hue, everything to do with deciding the amount—or, more accurately, the lack–of it. Diamonds are assigned one of 23 possible rankings from D (colorless) to Z (light yellowish or brownish). Using pre-graded comparison stones, known as Masters, gemologists find the closest color match from among the Masters to the stone being graded. A gemologist begins by placing the diamond being graded to the left of the Master Set to get a general idea of the color. Then they move the diamond to the right of the Master-diamond that is a bit more saturated than the diamond being graded. The grader continues to compare the diamond to the known Color Master diamonds until they determine the exact color. The difference between each color grade is very slight, but with experience, experts are
