The standard colour scale for white or ‘colourless’ diamonds is D to Z, ranging from completely colourless to heavily tinted with yellow or brown. Diamonds can either fall off this scale because they’re tinted with a shade other than yellow, or because the yellow colour inside the diamond is so strong that the diamond is no longer classified as a tinted white or colourless diamond, but rather a fancy yellow diamond. In this way, all diamonds that fall off the scale after Z are known as fancy diamonds.
Natural fancy coloured diamonds come in an array of colours, not only vivid yellow, and they are fancy because they are very rare. The different colours natural fancy diamonds include are blue, green, olive, yellow, brown, orange, red, pink, purple, black and grey. Each coloured diamond has a different level of rareness – and of course price is always a good indicator of rarity! It is said that there is only one coloured diamond for every ten thousand colourless diamonds.
It’s always very important to deal with reputable dealers when buying coloured diamonds as natural fancy coloured diamonds are much more expensive and valuable than laboratory treated coloured diamonds (which usually look much more saturated in colour and more like gemstones).