Most people don’t know that diamonds of all colors can be found in nature. Over 300 colors have so far been identified, however these come in an infinite number of shades and hues.
From pink to black, spanning all the colors of the rainbow including blue, red, yellow, green, gray and brown, natural colour diamonds are all excluded from the D to Z classification, which only applies to colorless ("white") diamonds.
Just like white diamonds, color diamonds are composed of carbon atoms
All diamonds have been formed at depths of 150 kilometers in the Earth’s mantle, under temperatures of 1300° to 2000° C and pressures circa 70 ton/cm². They result from geological transformations that took place between 550 million up to 4 billion years ago. Color diamonds have the same crystalline structure as their colorless counterparts, being the hardest natural material (10 on Mohs scale).
"Just like white diamonds, color diamonds are composed of carbon atoms"
And just like colorless diamonds, natural color diamonds are weighed in carats.
Color diamonds are found in their natural state in diamond mines that provide a vast majority of colorless gemstones. Indeed, color diamonds are much rarer than white ones: as little as 1 diamond out of 10,000 stones is considered to be a color diamond.
The colours of diamonds are due to many causes, the main of which being the presence of various amounts of other atoms.
Given their diversity but above all their rarity, laboratories have created a specialized nomenclature in an attempt to properly grade the quality of natural colored diamonds. Indeed, the criteria by which their quality is judged are very different from those used to evaluate colorless diamonds. The 4 Cs, for example, won’t be used the same way. To take the clarity criteria, the more saturated the color of a gem, the less important its clarity will be. As for the cut, natural color diamonds are cut following the same techniques as colorless diamonds, but differently: the goal being to find the perfect cut to emphasize the color.
Of course, these different criteria are specified in the natural color diamonds certificates. These define the hue (color) and intensity of the gem, following specific grades.
Most people don’t know that diamonds of all colors can be found in nature. Over 300 colors have so far been identified, however these come in an infinite number of shades and hues.