Step 7: Checking the Color Grading
The internationally accepted color scale, which was created by the GIA, starts at the letter D (which is the whitest color) and ends in Z (the most tinted with color). There are two color ranges in the diamond world. The most depicted is the Cape series, which shows as a yellow tint. There is also a brown series, which shows a brown tint. The brown tinted diamonds are less sought-after and therefore tend to fetch a lower value than the yellow.
Once we go beyond the end of the color scale, the diamonds would then move into the fancy colored diamond range. They consist of the colors yellow, pink, brown, blue, green, red, and orange. This is referred to as the hue of a diamond.
Looking at a loose diamond (i.e. when it is not set in jewelry) is the most accurate way to grade a diamond for color, and it takes a lot of experience to color grade. Once a diamond is loose, our graders can clean it and can then compare it on a color-grading tray in order to enable them to give it an accurate color grade. The process consists of turning the diamond upside down in a white color-grading tray and looking at the body color through the side of the stone. The reason graders do not look at the diamond from the top, is because the reflections from the diamond would interfere with their eye, therefore impeding their ability to assess the body color accurately.
Master stones are often used in order to grade the color of a diamond. These master stones are a set of diamonds or – sometimes even cubic zirconia – which have been produced and graded to GIA standards so that the grader can make a direct comparison with a color master stone in order to help determine the color of the diamond being assessed. Once the grader has assessed the stone from all angles, they will then allocate one of the GIA color grades to each diamond.
Looking at diamonds set in jewelry also takes a lot of experience. Furthermore, it is often more difficult with settings that surround the entire diamond as the light cannot pass through the diamond as easily. The color of the metal can also interfere with the appearance of the diamond, but an experienced grader will have the ability to grade the color despite this. It is also very important to make sure the diamond is clean as dirt will also interfere with the body color of the diamond.