Lab-grown diamonds color grading is the same as in mined diamonds – from D to Z, where D is colorless and Z stands for light yellow or brown tint. The easiest way to determine the color grade is to use a master set. The system of color grading used by GIA remained unchanged for more than 65 years already.
Depending on the cut of the diamond, the color difference between the grades will be more or less noticeable. For example, the difference in color will be easier distinguished in a radiant cut diamond, rather than a step-cut such as emerald. This happens due to the number of facets: the more facets – the better the color is locked “inside” the stone. Therefore, when choosing a diamond, it is more important to pay attention to color grade in shapes like radiant and cushion, and lower color grades can be tolerated in cuts like asscher and emerald.
Lab-grown diamonds color grading is the same as in mined diamonds – from D to Z, where D is colorless and Z stands for light yellow or brown tint. The closer the color of the white diamond is to colorless, the higher will be the price.
From Fancy Light to Vivid colored diamonds, the most valuable colors are considered to be pink/red, blue, while brown and yellow are the most common. Green diamonds are usually very light in tone and get their color from radiation, while pink diamonds get their color from the dislocations of the atoms.
The clarity in case of fancy diamonds is less important, while the price is much higher than the same carat weight of a pristine, flawless white stone.
Depending on the cut and size, the color of the stone can be more or less intense. For instance, to keep as much saturation in a fancy color diamond as possible, it can be cut using the mixed technique.
Black diamonds, on the other hand, are only graded on one scale: fancy black. Moreover, as they are black due to the high amount of impurities, their clarity cannot be distinguished according to the GIA clarity scale, and therefore, another type of certificate is issued: Colored Diamond Identification. With this certification, it can be known if the diamond is black naturally or if it has been treated in the laboratory.