The most significant characteristic of coloured diamond is its colour. In fact, unlike a colorless diamond where the 4C's (carat weight, clarity, color, and cut) are all equally important to the overall value, the pigment characteristic plays the most important role in the value of the diamond when it comes to colour.
The tint in Fancy shade diamonds is built from three parameters:
- The main color of the diamond
- The secondary hue of the diamond
- The intensity of the shade
The main pigment, and if there is a secondary tinge, together define the color tone, however the strength of color is defined by the intensity level. The intensity level can be anywhere from a very soft shade to a very strong shade, and the stronger the shade the more valuable the diamond is.
Gemological Institute of America (GIA) developed an intensity grading scale in order to categorize the intensity levels in the diamond. The eight grades in the scale are;
- Very Light
- Fancy Light
- Fancy Intense
- Fancy Vivid
- Fancy Deep, or Fancy Dark
For example, the following image depicts the full scale of pigment intensity in Pink, Blue, and Green color Diamonds. It is clearly shown that the intensity scale begins with very soft colors and progressively displays a richer tinted stone.
However, it is important to understand that every diamond its own levels of colour intensity levels. For example, Orange diamonds cannot be found in Faint, Very Light, or Light intensities. Only Fancy Light, Fancy, Fancy Intense, Fancy Vivid and Fancy Deep.
The GIA also defines how well the color and intensity is distributed throughout the stone. A diamond certificate will specify 'even' or 'uneven' according to the percentage of the color distribution.
Value of the stone has a direct impact based on its intensity of the color. For example a Blue diamond or a Pink diamond, which are rare in the fancy colored diamond family, are quite costly and difficult to find. However, there is a significant difference between a Fancy Light Blue and a Fancy Vivid Blue or a Fancy Light Pink and a Fancy Intense Pink.
Since there is such a wide range of colored diamonds, even stones of the same intensity can look quite different from one another. The intensity of each diamond is graded on a scale. The scale breaks down different stones of the same intensity grade between a weaker or stronger color.
Therefore, it is actually quite common to see two diamonds of the same intensity grade where one looks as if the color is more intense than in the other.
Exact color intensity of a diamond cannot be determined from the rough stone. However, the greater the color intensity of the rough stone, the greater the intensity of the polished diamond will be. How intense the color will be is also greatly affected by the diamond cut and shape of the stone. Also, the way colorless stones are being cut (Brilliant cut) is different from how Fancy Color Diamonds are cut (Modified).
The origin of the diamond is also another factor that affects the color intensity. Different diamond mines produce different shades or tones of colors. For example, a Pink diamond found in India or South Africa can't be compared to a Pink diamond found from the Argyle diamond mine in Australia.
I personally feel that if anybody is gifted/buy a diamond intensity would be the last thing in their mind when they get chance to chose one. However it also goes to say that the value of a diamond it actually calculated based on its intensity, greater the intensity higher the cost.