The GIA diamond color grades

Established in 1931, the GIA is a public-benefit, non-profit institute renowned for its gemological research. The GIA protects consumers through analysis, education, and gem grading and sets global quality standards. The GIA developed the definitive diamond color scale or chart in the early 1950s when there were many different and subjective terms for describing a diamond’s color, leading to inconsistency and inaccuracy.

Some of these terms included A, B and C, with multiple A’s used for the highest quality stones, as well as Arabic and Roman numerals and descriptions such as ‘gem blue’ or ‘blue white’. To avoid any confusion, the creators of the GIA color scale started with the letter D – a grade that had traditionally not been used or associated with top-quality diamonds. 

The 23 color grades on the GIA diamond color scale (or diamond color chart) are subdivided into five subcategories, which are as follows:

D – F: Colorless

G – J: Near colorless

K – M: Faint

N – R: Very light

S – Z: Light

What are the factors affecting diamond color?

While colorless or white diamonds are typically composed of carbon atoms arranged in a crystal lattice structure, colored diamonds owe their vibrant hues to the presence of trace elements or structural abnormalities during their formation, including pressure, temperature, and radiation exposure.

Grading of colored diamonds

Colored diamonds are exceptionally rare, with only 1 in 10,000 diamonds exhibiting intense coloration. The grading of colored diamonds is a complex and highly specialized process. The GIA grades colored diamonds on a scale that evaluates the intensity of their color, ranging from faint to fancy deep. The rarest and most valuable colored diamonds fall into the ‘Fancy Vivid’ category, displaying an intense and pure hue that is truly mesmerising.

Graff has been the custodian of many of the world’s most celebrated colored diamonds. Discover our high jewelry creations featuring rare fancy colored diamonds.

How a diamond’s cut impacts color

Different diamond cuts can influence how the color of a stone is perceived. A round brilliant cut is associated with concealing color compared to other shapes. This is due to their facets, which maximize the light that passes through the stone and make slight color hues less noticeable. In contrast, diamond cuts, such as the emerald cut, have long, open facets, which can make any traces of color more apparent.

How carat size impacts diamond color

The size of the diamond can impact the perception of color. Diamonds with a higher carat weight have a greater surface area, making color imperfections more visible. Therefore, as the carat size increases, you may consider a higher color grade to maintain a colorless or near-colorless appearance.

When selecting a diamond, it's important to consider the interplay between shape, setting, and carat weight in relation to color, as each factor can influence how diamond color is perceived. 

Our diamond experts can guide you to help you understand the nuances of a diamond’s color and how this impacts its overall appearance. Every Graff diamond is meticulously evaluated and assessed to ensure absolute perfection at every stage of a stone’s journey and according to the 4Cs as prescribed by the GIA.