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Diamond ColorPure diamond is colorless. Yellow color is caused by single substitutional nitrogen atoms trapped in the crystal, so-colled C form of nitrogen in diamond. Green diamond color may be induced by radiational damage. Blue color have diamonds with boron impurity. Brown and Pink color of diamond, by the opinion of scientists, is coused by plastic difformation of diamond lattice. Back color of diamon usualy coused by inclusions of graphite and sulphides. Prise of colored diamonds The Gemological Institute of America uses as "D" to "Z" scale for color where "D" is colorless and "Z" is yellow: - colorless: D, E, F
- near colorless: G, H, I, J
- faint yellow or brown: K, L, M
- very light yellow or brown: N, O, P, Q, R
- light yellow or brown: S, T, U, V, W, X, Y, Z
Colorless diamonds are priced higher than yellow diamonds. However, when a diamond's color is more intense than the "Z" grading, it enters the realm of "Fancy Color". In this case, the intensity of the color in the diamond plays a major role in its value. The value of a Fancy Color Diamond may far surpass that of colorless diamonds, if the intensity of the color is high and the color is rare. A diamond may come in all colors of the rainbow. A fancy brown diamond may have low value, relative to colorless diamond. However, a fancy pink or blue diamond will command higher prices. Fancy-colored diamonds such as the deep blue Hope Diamond are particularly valuable. Brown rather than yellow as the color became more common as Australian diamonds entered the market and is generally less appreciated by consumers and sold at a greater discount if the color is readily visible. 80% of the diamonds produced are poorer quality (discolored, less transparent) diamonds called bort which are used as industrial diamonds, where their extreme hardness is useful in cutting and grinding otherwise intractable materials (including other diamonds). Lately, gas-phase deposition processes have been devised that allow thin diamond films to be grown on some surfaces, greatly increasing the durability of some machine tools. While the prices are higher for colorless diamonds, the exact color most valued by a consumer is a matter of personal preference, with some preferring the very transparent D-F range, while others prefer the "warmer" colors in the G-J range and still others prefer a clearly visible tint. Many diamonds emit blue light when exposed to ultraviolet light. This fluorescence complicates color grading. See also References *Haske, Martin. GIA GTL's Color Grading Of Fluorescent Diamonds. (Retrieved March 15, 2005.)
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