In general, diamonds are considered particularly valuable if they are pure white without any yellow or brown tinge. An exception to this rule is the so-called fancy diamonds. This term refers to all diamonds that fall outside the usual color scale from D (very fine white +) to Z (yellow). In principle, diamonds can appear in all colors (white, black, yellow, brown, blue, green, red, pink or rose), but yellow and brown tones clearly predominate.
The following applies to fancy diamonds: the more intense the color, the higher the value. Due to their great rarity, the price of fancy diamonds is often much higher than that of colorless diamonds.
The Fancy Diamonds and their Colors
Yellow fancy diamonds owe their color to deposits of nitrogen, with the color intensity depending on the amount of nitrogen. A very famous fancy diamond with a canary yellow color is the 128.51-carat Tiffany diamond. The largest cut diamond in the world, called the Golden Jubilee , has a golden yellow hue.
Damage to the crystal structure is responsible for the formation of brown diamonds. A notable fancy diamond in this color is the pear-shaped Earth Star Diamond with a weight of 111.59 carats.
The element boron causes the coloration of blue fancy diamonds; prominent examples of such gemstones are the Hope Diamond and the Blue Wittelsbach Diamond .
In the case of the extremely rare green fancy diamonds, natural radiation is one reason for the coloration. A famous green diamond is the 41.0-carat Dresden Green in a pear cut. The rarest fancy diamonds are those in red, pink or rose - they get their color from internal damage in the crystal structure, which creates an absorption band at 550 nm. A well-known red example is the Red Diamond from Australia, which weighed 35 carats as a rough diamond. A pink diamond of considerable size is the Darya-ye Noor diamond from the Indian Golconda mines.
