How a modifying color will affect the diamond’s value will depend on its color.
In many cases, natural fancy color diamonds will present more than one hue, creating the variety of shades across the color spectrum. According to the Gemelogical Institute of America (GIA), there are a total of 27 color diamond variances. This includes hues such as Greenish Blue (aqua), Yellowish Green (lime), and Red Purple (fuchsia).
It’s not uncommon for gem laboratories to describe a diamond as having a combination of two or three colors. When this occurs, the last color named is the primary color of the diamond while the modifier is the secondary or tertiary color. Therefore, a Yellowish Green diamond will have a primary color of yellow with a blue modifier.
How a modifying color will affect the diamond’s value will depend on its color. The rarer the color, the more valuable a color diamond will be, so certain modifiers will increase the stone’s value while others will decrease it. For example, if a diamond has an extremely rare modifying color such as red, it will be far more valuable than if it has a modifying color such as brown or black. When both colors are rare, not only will the diamond retain its value, the value may even increase thanks to the combination.
In some cases, the suffix –ish may be placed behind the modifying color (i.e. Bluish, Greenish, Pinkish, etc.). When you see this suffix, it means that the modifying color makes up between 15 and 30 percent of the diamond’s body color. If the color modifier is less than 15 percent of the diamond’s body color, it is not mentioned. If the modifier makes up between 40 and 45 percent of the diamond’s color, the full color name is used (i.e. Blue-Green, Orange-Red, etc).
At Guildhall Diamonds, we only choose stones with the rarer (and therefore more valuable) modifiers for our collection in order to ensure the appreciation value of each of our diamonds.