Color
The
color of a diamond or gemstone can be described on a scale. Color scale is carefully compiled by gemologists who compare absolutely colorless (very valuable) diamonds with colored ones. For diamonds, the scale range is from D, which means that the diamond is absolutely colorless, to Z which shows distinct yellow-brown nuance. Gemstones are graded among other things by their tone and color saturation.
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Diamonds color,
Types of gemstones