To determine a diamond’s Color grade under non-laboratory conditions is very difficult, even for an expert. Most people can easily see the differences in color if they compare two diamonds with color grades that are at least two or three Color grades apart.
To help you select the most brilliant diamond, we only offer diamonds with the best grades of color (grades F to H). Diamonds with D and E color grades are available by special order.
The Gemological Institute of America (GIA) and the American Gem Society (AGS)have devised the following color grading scale for diamonds:
The Z+ or FANCY grade refers to those exceedingly rare diamonds that are deeply colored. These deeply colored diamonds are usually canary yellow, but red, pink, blue and green are also seen.
Additional criteria, such as Fluorescence, Hue and Color Saturation, are also utilized to determine theColor grade of Fancy diamonds. Some of the world’s most famous diamonds include the Hope Diamond (deep blue) and the Dresden Green Diamond (deep green) are Fancy diamonds.
Light yellow to light brown or “champagne” colored diamonds are occasionally offered for sale as Fancy diamonds. These light brown or “champagne” colors are not considered to be in the Z+ grade by the GIA.
Fluorescence: Diamonds have the ability to fluoresce under ultraviolet (UV) light. Natural sun light contains some UV light, but it is not enough to detect fluorescence. Some diamonds will emit a distinctive blue glow when exposed to UV light, although other colors occasionally occur.
Fluorescence is graded by intensity and is classified as None, Faint, Medium, Strong and Very Strong. Fluorescence only becomes an issue when evaluating Colorless (D, E and F grades) and Fancy (Z+) diamonds.
For an indepth look at fluorescence, read this section here: https://beyond4cs.com/grading/fluorescence/
The Key Point to Remember: For Color Grades, the closer the letter is toD, the better.