D iamonds occur in an array of colors – from pure whites and soft pinks and blues to brilliant hues of purple and red. No matter the color, each stone possesses a unique composition of chemical elements that have the power to dictate rarity, value and desirability.
How Do Diamonds Get Their Color?
White diamonds are the most common, falling into the largest color spectrum on the Diamond Grading Scale, which begins with “D” color, meaning totally colorless, and ending with “Z” color, which is pale yellow or brown.
The variable in this spectrum is the element nitrogen – a D color diamond has no nitrogen (or only a microscopic amount) nor any other element present. The larger the amount of nitrogen present, the more the color increases, thus moving the diamond along the color spectrum.
The vast majority of white diamonds mined today have a large content of nitrogen, which classifies them towards the lower end of the color scale. Diamonds that fall within the D–F color range are rare, and therefore more will command a higher price than those towards the end of the spectrum.
Colored diamonds contain impurities or structural defects within the chemical composition. In the case of yellow diamonds, nitrogen is incorporated into their carbon crystal structure. These nitrogen impurities give a diamond its yellow color as they modify light and absorb the blue part of the visible spectrum.
When there is a large amount of nitrogen present within the stone, the diamond ceases to become a M–Z colored diamond and becomes a fancy colored diamond. All fancy colored diamonds follow the same color grading scale: Fancy Light, Fancy, Fancy Intense and Fancy Vivid. As the color concentration increases within the stone, so does its value.
Blue diamonds are caused by boron, a rare element in the Earth’s crust.
Many are modified with a gray secondary tone or an uneven saturation with areas of colorless windowing, making natural blue diamonds with exceptional saturation and brilliance extremely rare.
Pink, Red & Other Colored Diamonds
Other colors, such as green, purple and orange, occur from natural radiation and other common elements within the Earth. Colored diamonds are truly an anomaly of nature.