Coloured Diamonds

In the world of diamonds rarity undoubtedly equals value. Therefore with only one in 10,000 diamonds having a fancy colour, it can be seen why with their rarity, dazzling brilliance, and unique exquisite colours, many experts consider Natural Fancy Coloured Diamonds to be the most highly prized gems.

Colourless Diamonds only contain different shades graded in GIA’s D-to-Z range and they are valued upon their absence of colour, with totally colourless diamonds being the rarest and most valuable. Natural Fancy Coloured Diamonds, also referred to as ‘Fancies’, are the complete opposite. They are yellow and brown diamonds that exhibit colour beyond the Z range, or diamonds that exhibit any other colour face-up. Their value usually increases in relation to the colour, so the deeper the colour the higher the value, and stones outside of the normal colour range are considered the rarest.

Natural Fancy Coloured Diamonds present in a veritable rainbow of colours with 12 different colour variations, over 90 secondary hues, 9 intensity levels, and more than 230 combinations of colour.

Their colours are muted rather than strong and pure as they are often blended with other colours and muted by greyish or brownish tones. This means that the value of a Natural Fancy Coloured Diamond generally increases with the purity and strength of its colour i.e. large vivid coloured stones are considered to be extremely valuable as they are a very rare find.

The rarest, and therefore the most valuable, colours of Natural Fancy Coloured Diamonds are said to be red, green, purple and orange diamonds with medium to dark tones and moderate saturations, followed by blue and pink. The most common colours are browns and yellows. The colours of black, grey, and fancy white are also found in Natural Fancy Coloured Diamonds. Perhaps the most famous Natural Fancy Coloured Diamond is the 67.50 carat cushion-cut black diamond the ‘Black Orlov’ alternatively known as ‘The Eye of Brahma’.

As with Colourless Diamonds, the value of Natural Fancy Coloured Diamonds is gauged according to the 4Cs - Diamond Colour, Diamond Clarity, Diamond Cut, and Diamond Carat Weight. However due to the uniqueness and rarity of Natural Fancy Coloured Diamonds, the colour of the stone is ranked as the most important attribute for defining the diamond’s value.

In contrast to Colourless Diamonds, a Natural Fancy Coloured Diamond with numerous inclusions which would result in a low clarity grade will be highly valued by a connoisseur of Fancy diamonds if the face up colour that the diamond displays is very attractive. However, as with Colourless Diamonds, inclusions that will impact upon the durability of the gem can significantly lower a Fancy colour diamond’s value. Natural Fancy Coloured Diamonds can of course exhibit colour graining which is considered an inclusion.

Within the international jewellery trade there is a consensus of opinion that Natural Fancy Coloured Diamonds should display certain features which classify them as true ‘Fancies’. These features are the presence of either a yellow or brown colour (with a higher colour than a Z master stone), or a colour other than yellow or brown.

Grading Natural Fancy Coloured Diamonds is a very specialised and complex task. This is due to the fact that Natural Fancy Coloured Diamonds come in so many shades which means that there are simply too many variations to make a complete set of master stones. Therefore when the highly trained diamond graders at the GIA Laboratory grade Natural Fancy Coloured Diamonds, to assist them in identifying the colour of the diamond or its characteristic colour, they use a combination of comparison stones and printed standard colours.

The GIA system for grading the colour of Natural Fancy Coloured Diamonds has been designed to take into account the fact that not all coloured diamonds have the same depth of colour. For example, yellow diamonds are more widely found while blue diamonds are rarer.

Once the diamond's characteristic colour has been determined it will be assigned a colour grade which consists of a characteristic colour modified by one of these grade terms:

• Faint 
• Very Light
• Light
• Fancy Light
• Fancy
• Fancy Intense
• Fancy Vivid
• Fancy Dark
• Fancy Deep

Faint, very light and light are applied to all colours excluding yellow. Any diamond that shows a natural yellow colour which is stronger than the Z master stone will be termed ‘fancy light yellow’.