The GIA developed the fancy coloured diamond grading scale in the mid-1970s due to a rise in popularity of fancy coloured diamonds. The GIA therefore needed to develop a standardised way of classifying and understanding the stones. Due to the large number of colour combinations present in the fancy coloured diamonds they decided to rather use a description rather than a letter as it is done with regular diamonds.
Fancy Coloured Diamonds are graded on a different scale to regular diamonds. With regular diamonds one uses single letter grades as see here.
The Fancy coloured diamond scale developed by the GIA looks like this.
With fancy coloured diamonds the basic colour of the diamond must be determined and compared to a set of predefined reference diamonds. The GIA developed a grading system that makes use of colour space areas which are split into ‘boxes’ (see below) Reference stones are then placed into these specific “boxes” according to their colour and hues.
The GIA developed a grading system that makes use of colour space areas which are split into ‘boxes’ (see below) Reference stones are then placed into these specific “boxes” according to their specific colour and hues. The diamond being graded will then be placed in one of these boxes for comparison to find a colour characteristic that closely matching its own.
The implementation of the grading methodology is done in a standardized manner for the grading results to remain consistent every time.
Defining the Colour of a Diamond
The GIA’s fancy colour grading system for fancy colour is based on 3 main attributes ofaspects, tone, hue and saturation.
Hue refers to the primary colour of the diamond such as green, red, blue, brownpink etc… In total,. The GIA currently recognizes 27 different hues and each of these hues have awith their own range of possible colours.
Tone defines how dark or light the hue of the diamond is.
Saturation refers to how intense the coloration of the diamond is.
Colour descriptions assigned by GIA
Generally speaking the darker the hue, the more valuable the diamond. The colour can be anywhere between a faint hint of colour to a bold and vivid shade. The GIA developed an intensity scale to accurately define the level of intensity the diamond has.
The GIA colour grading system have nine grades to distinguish the colour range of the diamond, the grades assigned are based on the overall effects of the diamond’s hue, tone and saturation. The main grades are: Fancy Vivid, Fancy Intense, Fancy Deep, Fancy Dark, Fancy, Fancy Light, Light, Very Light and Faint.
Warmer hues like yellow red and orange gradually appear to look brownish as their saturation decreases. Cooler shades like green and blue tend to gravitate towards a more greyish colour.
Whilst the carat, cut, and clarity are all extremely important factors when grading the quality of the diamond, the colour and intensity of the diamond are the most relevant characteristics when assessing the value of the diamond.
Every detail counts when grading a coloured diamond as the smallest mistake could be the difference between thousands of diamonds. The GIA grading system is understood and accepted throughout the world so when it comes to fancy coloured diamonds it is advisable to make sure that your diamonds has been graded by the GIA.