Fancy Colored Diamonds (Canary)
Range from Vivid to Light
Diamonds used in jewelry are basically transparent or colorless with little hint of yellow or brown. The most common impurity in diamonds is Nitrogen, with small proportions of carbon atoms in a diamond's structure are replaced by these Nitrogen impurities which causes a yellowish to brownish tint.
Yellow diamonds exist in different tones from Light Yellow to Fancy Intense Vivid Yellow (also known as Canary Yellow), depending on the amount of Nitrogen is fused in the diamond (concentration) when the crystal was formed. Yellow colored diamonds are often more desirable than colorless diamonds, due to their warm yellow color. Inclusions in fancy diamonds are less noticeable to the eye because of the diamond’s rich color. The inclusions do not affect the look and sparkle of a diamond unlike their colorless counterparts.
A natural fancy coloured diamond is rare and very expensive but most people believe that these yellow diamonds are less valuable than their colorless counterparts. While this is true on faintly coloured or off-white diamonds, intensely coloured diamonds are very attractive, rare and not to mention, very expensive. The Kimberley Octahedron is a yellow diamond and is considered the largest diamond in the world at around 616 carats.
Grading fancy color diamonds
Yellow or brown colored diamonds having a color grade more intense than "Z", as well as diamonds exhibiting color other than yellow or brown, such as blue or pink are also considered fancy colored diamonds. These fancy diamonds are graded using a separate systems which indicate the characteristics of the color. These color grading systems are similar to those used for colored gemstones, such as sapphires, rubies, topaz or emeralds.
Colored diamond grading system
GIA and EGL-USA issues a Colored Diamond Grading Report for colors that are not in the normal color range of diamonds. The following are terms used to describe natural yellow diamonds:
Fancy Intense Yellow - this range of diamonds have richer color and quality. The value of this kind of diamond are higher compared to Fancy Yellow diamonds.
Fancy Yellow - a lesser saturated yellow hue compared to the Fancy Intense Yellow diamonds which makes it a little cheaper compared to the other 2 ranges but still quite valuable.
Light Fancy Yellow - a slight yellow tint that can be detected by human eye. Lighter shades are a great value because they still look yellow, yet you can have more size for your money.
In this age of technology, Sarin Technologies, has developed a device called Gran Colorimeter, that can determine a stone’s color grade. This device can measure from D to Z to Fancy Intense with an accuracy within ±½ of a color grade on loose diamonds from 0.25 - 10 carats (it can go as low as 0.15 carat and as high as 20 carats with a reduced accuracy). The Gran Colorimeter can be set to which ever grading scale it should use (GIA, EGL, GEM, IGI, AGS, HRD, etc…). The accuracy is reduced within ±1 color grade for mounted diamonds mounted on jewelry. If your diamond is a "G" color it can even tell whether it’s a "High G" or a "Low G". Paul Gran originally developed the first Gran Colorimeter in 1972 at Gran Computer Industries Ltd.