Refers to a grading scale for diamonds in the normal color range used by internationally recognized laboratories . The scale ranges from D which is totally colorless to Z which is a pale yellow or brown color. Brown diamonds darker than K color are usually described using their letter grade, and a descriptive phrase, for example M Faint Brown. Diamonds with more depth of color than Z color fall into the fancy color diamond range. While several grading laboratories use the D-Z color scale , there is no universal standard for how the grades are applied. The same diamond submitted for grading at two laboratories employing the same color scale nomenclature, will often receive conflicting grades.
Diamond color is graded by comparing a sample stone to a master stone set of diamonds. Each master stone is known to exhibit the very least amount of body color that a diamond in that color grade may exhibit. A trained diamond grader compares a diamond of unknown grade against the series of master stones, assessing where in the range of color the diamond resides. This process occurs in a lighting box, fitted with daylight equivalent lamps. Accurate color grading can only be performed with diamond unset, as the comparison with master stones is done with diamond placed on its table facet and pavilion side facing upwards ( i.e. "upside down"— resting on the face one normally looks at). When color grading is done in the mounting, the grade is expressed as an estimated color grade and commonly as a range of color. Grading mounted diamonds involves holding the mounted diamonds table close to the table facet of the master stone and visually comparing the diamond color under the same color conditions as unmounted diamond grading. The resulting grade is typically less accurate, and is therefore expressed as a range of color. While a grading laboratory will possess a complete set of master stones representing every color grade, the independent grader working in a retail environment works with a smaller subset of master stones that covers only the typical grade range of color they expect to encounter while grading. A common subset of master stones would consist of five diamonds in two grade increments, such as an E, G, I, K, and M. The intermediate grades are assessed by the graders judgement.
Diamond Color Grade
D Colorless : A D color diamond possesses the highest color purity and is a symbol of perfection. It is considered extremely rare and has no recognizable shades of color. When looking at a diamond with the naked eye, E and F colors can also look similar to the D color diamond. A D color diamond looks best when set in white gold and platinum, as the white color of the metal further highlights the colorless quality. However, D color diamonds can also look beautiful in rose and yellow gold, but some color from the setting will come through the stone.
E Colorless : An E color diamond is visually stunning and has very high color purity. It is incredibly rare and has almost no recognizable color shading. To the naked eye and even under 10X magnification, an E color diamond will not show any tinges of yellow color.
F Colorless : An F color diamond has excellent beauty and contains a minute shade of color that is undetectable by the untrained eye. It is also very rare and considered to have high color purity. When looking for a diamond that will not exhibit shades of yellow to the naked eye, and F color certainly fits the bill and can be more affordable than a D or E color diamond.
G Near Colorless : A G color diamond is exquisite and has minor traces of color that can be identified only by diamond professional. It is also the most popular diamond color and provides a great blend of beauty and value. A platinum or white gold setting can work to hide traces of yellow color in the ring, however a G color diamond is versatile and can look great with rose and yellow gold.
H Near Colorless : An H color diamond has gorgeous appeal as its slightly identifiable shade of color does not affect the diamond’s brilliance. It is one of the most popular colors because of its visual attractiveness and value. An H color is a good balance between these factors and can be a great choice if you're trying to maximize for other characteristics like carat or clarity.
I Near Colorless : An I color diamond delivers excellent brilliance even as some shading of color can be identified by a gemologist. The color is still not recognizable to an untrained eye and provides excellent value. Depending on the diamond, an I diamond can be a good choice as the yellow color is not too perceptible. However, it is a good idea to ask a gemologist to help you find a stone that faces up white before making your purchase.
J Near Colorless : A J color diamond has exquisite sparkle and value (as long as you’re getting a stone that’s cut well, of course). It has a shade of color that is only detectable by trained professionals and allows for a larger size or higher clarity that may be more palatable to your budget. Talk to a gemologist to help you find a stone that faces up white and discuss the diamond shape you’re considering, as some amplify the color of your diamond.
K Faint Yellow : A K color diamond is considered a white diamond that does not compromise the stone’s sparkle. Some shading of color may reflect in light, but it is still difficult for the untrained eye to identify the color grade. Keep in mind, though, that a K color diamond can look yellow to the naked eye, especially in larger diamond sizes over 1.50 carats.
L Faint Yellow : An L color diamond is scintillating and considered a white diamond that does not distract from the diamond’s sparkle. Slight color may be detectable to the untrained eye, especially when viewed from the side. It looks best in yellow gold settings, which minimize contrast between the diamond and the setting. Check with a gemologist before purchasing an L color diamond to ensure that it is the correct color for you.