We are going to explain a little about diamond colour, more specifically how diamond value is influenced by whiteness.
What about A, B and C?
Let us begin first of all by answering one of the most frequently asked diamond questions relating to the whiteness scale for colour grading. “Why does the grading system start with D?”
Prior to the adoption of the GIA diamond grading system for colour, there were a multitude of other systems in place. Some members of the industry used letters A, B and C without any clear and concise relation to specific colours, and some systems even used an AA grading for diamond colour. Other traditional terms such as Wesselton and Top Wesselton represented multiple grades of whiteness and were easily confused.
Starting afresh, GIA opted for symbols that were disassociated from any systems in place before. For this reason, the colour scale was introduced starting with the letter D.
To this day, the GIA diamond colour scale, running from D – Z is the most widely adopted system for grading whiteness in diamonds. As we move away from D colour, diamonds become progressively less white, with yellow or brown tinges being clearly visible further down on the scale. It was first introduced by R. Liddicoat of the Gemological Institute of America (GIA) back in the 1950’s. The colour of a diamond is determined by the combination of tone (light/dark) and saturation (concentration.) The depth of colour is a combination of these two factors which determine how noticeable the colour is. Here, are a few interesting facts relating to diamond colour.
Interesting Facts about Diamond Colour
- It is possible to be colour blind and still successfully grade diamond whiteness
- Diamonds are graded under constant white light produced by daylight tubes
- Diamonds are graded within a neutral, plain background, to avoid surrounding colours interfering
- Natural blue fluorescence can improve the appearance of colour in tinted diamonds
- “Master” sets of diamonds is generally used to compare diamond colour with the stone being graded
- G to I colour diamonds are exceedingly hard to distinguish for colour when set into a ring
Whiteness & Diamond Value
When most people think of a diamond, they rarely consider that there are so many differences by way of colour. Most people are aware of fancy coloured diamonds, but rarely understand the effect that whiteness can have on the stone’s value. Two diamonds of the same carat weight, cut, and clarity will differ significantly in value due to a subtle colour difference. This is essentially due to the rarity of whiter grades of diamond. The nearer to colourless the diamond is, the rarer and more valuable the stone will be. The largest jump in the price per carat is experienced in the leap to a truly colourless diamond.