4C's Handbook - Diamond Color

Diamond Education Handbook

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Many consumers are surprised to hear that diamonds come in a wide range of colors. Recently, fancy colored diamonds like pink, blue, and green have become very popular for diamond jewelry and engagement rings. These diamonds are considered to be very rare and valuable however, they are not what most people envision when considering a traditional diamond purchase. For the most part, the normal diamond color range consists of the colorless (lack of any color), very light yellow, and light browns. The diamond industry has created a universally accepted scale that rates the various shades and depth of color that a diamond may have within this normal range.

Diamond Color Grading Scale

The Gemological Institute of America devised the color grading system in the 1950's using what is now known as the "D-Z" scale. The "D-Z" scale describes the normal color range D (colorless) to Z (light yellow or brown). The D-Z scale will not describe actual colors, or hues such as brown, yellow, white, and blue. Each letter will represent a range of intensity or specific presence or lack of presence. Some diamonds have no color at all and some diamonds have a lot of color. For example, if you were to look at an ice cube made of tap water you would notice that is has no color (D). If you were to examine an ice cube made of lemonade you would notice that is has a slight yellow color (Z). You could also examine an ice cube made of root beer and notice that is has a slight brown color and this too could be (Z). When using the D-Z scale, the color grade of a diamond is not affected by the actual color yellow, brown, gray, etc. The grade is affected by the intensity or depth of whatever color the diamond has. The root beer ice cube could be made with a partial solution of 50% water and 50% root beer and then the intensity of the brown may drop to a (U). It's still brown but a much lighter brown because you have diluted the depth of color. A very good analogy for understanding the diamond color chart is that (D) is icy cold and (Z) is very hot and anything in the middle is lukewarm.

Compare Color Grades

Grade D Diamond

Grade D


Grade K Diamond

Grade K

Faint Color

Diamond Color Scale

The reason for the sub categories is because the color grades within each category look more closely like one another than neighboring colors. When compared side by side, a diamond graded (G) color looks more like an (H) than a diamond that is graded (F) even though the (G) neighbors both colors. You might say that color grades grouped in the colorless range are brothers & sisters and the neighboring near colorless group are their cousins.

The actual diamond color grading process is done using a side-by-side comparison under controlled conditions. The un-graded diamond is compared to a collection of round diamonds of known color. These comparison diamonds are called master-stones and each color represents the least amount of color in its color range. Accurate color grading is extremely dependant on the master-stones, the environment, and the grader. While gemological advancements have aided in the color grading process each color grade actually represents a range of color not an exact color. Sometimes a diamond will fall on the borderline between two color grades and the grader is challenged with the decision of where to place the diamond on the grading chart. There is no exact science to color grading and sometimes the same diamond can receive different grades from different gemologists. That is why it is very important to have your diamond certified by a creditable gemological laboratory like the Gemological Institute of America or the European Gemological Laboratory. Even then the grade should not be taken literally because diamond grades for color and clarity are only a matter of opinion; they are not an exact science.

When choosing the color grade that will best suit your needs you should consider how the diamond fits in your budget and how the diamond will look in the metal type you have decided on. Of course everyone desires the highest quality diamond possible however, not everyone can afford a (D) color. Platinum, white gold, and palladium jewelry will hold a diamond as low as (I) color nicely and then anything below that starts to show large amounts of yellows or browns. A good rule of thumb is to consider diamonds of (I) color and better when choosing a white metal. Yellow gold jewelry on the other hand can hold diamonds as low as (KL) color and still look quite nice while saving you considerable amounts of money. When diamonds are set it is very difficult to determine exact color grades and that's why it's not imperative to have the highest quality color grade.

What is Fluorescence?

Diamonds often emit a color reaction when subjected to ultraviolet light. Diamond fluorescence is graded on a scale from "None" to 'Very Strong." Most often diamonds fluoresce a blue color, however other colors are possible. If the fluorescence of a diamond is stronger than "Faint", most grading laboratories will note the color of the fluorescence on the report. Fluorescence can add an interesting quality to a diamond and can actually help diamonds look nicer when they have a lower color grade as in K- M, however, a very strong fluorescence can affect its value.

What Color Grade Should I Choose?

The best-kept secret in the jewelry business are (H) and (I) color diamonds. These diamond color grades can stand up against even the highest of color grades while maintaining their beauty and saving you money. When shopping for diamonds be sure to look at actual diamonds that have been certified for color; examine diamonds from the colorless, near colorless, and faint color categories. Use the side-by-side comparison to see if you can notice the differences from one diamond to another and then consider the price difference to decide if it is justifiable to invest more. You may decide that only a higher color quality will make you happy; everyone has different needs and taste but careful investigation is the only way to reach a safe and proper conclusion.