Color is a big part of the quality of a diamond. When you come to our custom design jeweler in Seattle and Bellevue, even the slightest difference in a diamond’s color can make a big difference in price.
The Gemological Institute of America (GIA) uses a color grading scale starting at D, the best possible color grade for a diamond, all the way to Z, which is the lowest. Stones that have more color than Z are considered to be fancy colored diamonds, which can command high prices due to their rarity. These fancy colored diamonds may be intensely yellow or brown, or even exotic colors like pink, red, green, and blue. The 45.52 carat Hope Diamond, quite possibly the most famous diamond in the entire world, is a stunning blue shade and worth $200-250 million.
The normal color range of diamonds spans a pale yellow all the way down to a brown hue, and the majority of mined diamonds fall within this range. Diamonds in the normal color range are what we consider "white" diamonds, and are the kind most commonly used in engagement rings. Even though most diamonds appear colorless to the naked eye, the majority of diamonds contain traces of yellow or brown. Chemical impurities or structural defects can both affect the natural hue of the stone. The closer the stone is to colorless, the more valuable the diamond. Totally colorless diamonds appear bright white, and are very rare and very, very expensive.
When GIA is grading a diamond’s color, the diamond must be loose so it is not influenced by the color of surrounding metal. It is then viewed in a specially controlled environment that eliminates any outside influences such as color from nearby objects or a tinted light source. The stone is compared "face down" (pointy side up) to a set of diamonds known as a masterstone.
These masterstones are prime examples of the full range of diamond colors, which each grade represented by a diamond that exhibits the least amount of body color permissible within that grade. Thus, a lab grader will compare the diamond side-by-side with each masterstone until the proper color grade is determined. Stones in the higher color grades will appear even whiter and brighter when they are properly mounted "face up" in their final setting.
Masterstone Set, picture courtesy of the Gemological Institute of America
Without comparing it to a masterstone set under ideal conditions and with an experienced eye, it is nearly impossible to determine the exact, accurate color grade of a diamond.
Since a diamond reflects the color of its surroundings, colorless diamonds, such as those graded D-F, are at their best when mounted in platinum or white gold. The bright white/silver tones of these medals will allow the diamond to shine, while a yellow gold or other colored metal would actually reflect onto the diamond, making it appear a darker shade than it actually is.
When choosing a diamond for their engagement ring, some buyers will settle for nothing less than perfection. For budget minded shoppers, however, anything above a J grading can be a better choice. Anything graded K and below will be tinted with increasingly visible shades of yellow and brown. While one of these stones may still be a suitable choice in certain circumstances, cut and setting will be even more important to maximizing the better qualities of the stone.