To the unaware buyer, diamonds all look the same – except for the size and the shape they are cut in. But they all appear sparkly and colourless. And to the naked eye, that is, for the most part, true. But diamonds are not all colourless. In fact, an actual colourless diamond is very rare. Most diamonds have yellow, green or brown tints to them, although most that can be found at reputable jewellers only have colour that can be seen under a microscope and is not apparent to someone just admiring the ring.
The colour scale is how gemologists grade diamonds. It ranges from D, which is colourless, to Z, which is light yellow and detectable to the naked eye. Any diamond rated below Z is considered a fancy coloured diamond and is much rarer and thus more costly than a white diamond.
• D Absolutely Colourless – Incredibly rare.
• E, F Colourless – Rare. Colour is detectable only by expert gemologists.
• G-J Near Colourless – These diamonds have a slight warmth to them, only noticeable when compared to colourless diamonds.
• M-Z Noticeable Colour – These diamonds have colour visible to the naked eye, even when they are not compared to other diamonds.
Most buyers choose a diamond in the D to J colours. After J, colour can be visible to the naked eye and decreases in value. Many jewellers will not carry diamonds past a certain grade on the scale.
Some diamonds can appear to give off a blue glow under certain lighting. It is more common than one would think. Almost 50% of all diamonds have a fluorescent quality, although only 10% of that have a strong enough quality to be detected. In colourless diamonds, fluorescents are a an undesirable quality that decreases the value of the diamond, but in J-K diamonds, it increases the value.
If the diamonds have a very intense colour, they actually go up in value. These diamonds are called fancy colours and can come in reds, blues, yellows, pinks, oranges, and browns, although yellow is the most common of all the fancy colours. Fancy coloured diamonds are very rare and can cost much more than white diamonds.
Sometimes they have a secondary colour as well, such as bluish red, or greenish yellow. Red or yellow would be the predominant colour, and the blue or green would be the secondary tint that can be detected in the diamond. For a diamond that seems equally two colours, it would be called orange brown or blue pink.
Coloured diamonds are cut to maximize colour, unlike white diamonds that are cut to maximize shine and sparkle. The more intense or deep the colour of the diamond is, the more its value goes up. So cutting it to make the most of its colour is increasing its value.
There are heat and other treatments that can be applied to make a fancy coloured diamond more intense. However, utilizing these treatments decreases the value of the diamond. Many reputable dealers will not sell treated diamonds.
What is the Right Colour for Me?
The colour grade that is right for you depends primarily on your budget. It is beneficial to keep in mind that most diamonds sold by professional, reputable jewellers do not have noticeable colour. So if you are on a tight budget, it may be better to go with a lower graded diamond, especially considering that once it is in its setting the colour will be virtually impossible to detect.