The Four C’s – Color Grade
A diamond’s body color is that property, which is an inherent characteristic of the crystal itself, which gives the diamond its color. Diamond colors can vary widely from colorless, (also called white), to the fancy colored diamonds, which is a term used to describe basically any desirable color of diamond other than white. Fancy colored diamonds can be found in brown, yellow, blue, green, pink, and red, and occur in various degrees of hue, saturation, and intensity. Colored diamonds can be classified into two categories: as untreated, unenhanced, naturally occurring diamonds, or as treated/enhanced colored diamonds. The color grading system described here was developed by the Gemological Institute of America, (GIA). It is the standard grading system used in the U.S. and, for the most part, around the world. Diamond color grades are represented by letter grades starting at “D”, which is completely colorless, the absolute best colorless grade, and goes all the way to “Z”, which would be a very obviously brown, or brownish-yellow color. After “Z”, the fancy color grading system is used. Typically, for white diamonds you will only see grades “D” through “M” or possibly “N”. Grades are grouped in three major groups:
- Colorless — D, E, and F;
- Near-colorless — G, H, I, and J;
- Faint yellow — K, L, and M;
- Very light yellow — N – R;
- Light yellow — S – Z.
Diamonds are graded with the table side down…this means upside down to the way they are mounted. Thus, when a diamond is mounted in a setting, this usually makes accurate color grading impossible using a color master set. Newer technologies now make it possible to color grade a diamond while mounted, but these instruments are very expensive and not widespread. Diamonds presented for grading, which are mounted, will only be a “best estimate”. Color master-sets are typically used to color grade diamonds. These master-sets are diamonds, or CZ’s that have been compared against a master-master set, and can then be used to compare to other stones. The GIA maintains such a master-master set of diamonds at the Gem Trade Lab in Carlsbad, California. Other means of color grading include newer electronic technology to grade the stone automatically.
Diamond market color preferences vary and are individual in nature. For some, diamond color is highly important and only a colorless diamond will do. For others, diamonds in the near-colorless range are good enough. Diamonds mounted in platinum may require a better color grade to ensure the color tint does not show against the pure white of the metal. Color grades of G through J can be mounted in white gold, which has a slight yellowish tint to it which can tend to hide the lower color grade of the stone. Another factor that can affect the way a stone looks is the quality of the cut. A very good quality cut can help mask the color in stones that have a yellow or brown tint to them. By paying a little more to get a stone with a better cut, you can save on the color side of costs by getting a lower color grade without sacrificing the look of the diamond. Nicer cut diamonds, of poorer color grades can look much whiter than the color grade would suggest since the quality cut allows less light leakage and thus more white light is directed out of the top of the stone “bleaching out” the natural body color.
Another factor that can affect color is fluorescence. Fluorescence is the property of a stone that determines how a diamond will react to ultraviolet, (UV), radiation…a component of sunlight. Ultraviolet light, (radiation), occurs in two forms: long-wave, (LW), and short-wave, (SW), radiation. Many are familiar with the “black-light” sometimes used in nightclubs, which give off that purple color light and makes certain colors really glow. This is an example of the type of LW ultraviolet light mentioned here. Diamonds can sometimes react to either this LW or SW UV by glowing blue or, less frequently, yellow-green. The reaction can be anywhere from very faint to very strong. Typically, a diamond with moderate to strong fluorescence will be less expensive that another stone that is equal in every other way. However, this property of a diamond can be of some benefit when found in diamonds with higher levels of yellow or brown body color. A diamond that reacts with a faint light blue glow in ultraviolet light…sunlight…will appear to be whiter than it really is in light that does not have a UV component. Thus you could pay less money for a stone with a poorer color grade, and some fluorescence, to get a similar look of a “whiter” diamond.
Thus, a diamond will have a basic, inherent body color, however, you can see how many factors can work together to affect the appearance of that diamond. Consulting with your diamond expert can ensure you get the most for you money, in the quality that is important to you.