Are you interested in coloured diamonds?
Coloured diamonds are particularly rare and valuable gems. There is only one coloured diamond ‒ also known as ‘fancy diamond’ ‒ in existence for every 10,000 colourless diamonds. In addition, the majority of the gems, which occur in over 300 different colours, are generally very small, at weights of under one carat. Unlike colourless diamonds, the value of coloured diamonds increases with the intensity (or saturation) of their colour.
Coloured diamonds - the different types
Coloured diamonds are available in virtually all colours and in an enormous range of hues and intensities. The stones developed their colour from deposits of boron, hydrogen and nitrogen in the earth‘ s crust. In a process spanning millions of years, these substances caused the crystalline structure of the stones to change and adopt the various colours. Synthetic or treated coloured diamonds cannot be compared with these one-of-a-kind gems, created by nature alone.
Please contact us
Are you interested in loose coloured diamonds, or would you like to incorporate a coloured diamond into a stunning piece of jewellery? We will be happy to provide detailed advice about quality criteria and properties of these elegant diamonds to make your vision of a special coloured diamond come true.
Or call us: UK +44 20 351 466 05 International +49 89 1222 893 0
Coloured diamonds (fancy diamonds) ‒ Fascinating gemstones
A rainbow of coloured diamonds
Colourless (clear) diamonds are graded on a scale from D to Z, where D is the purest, and thus the best and most valuable colour grade for a clear diamond. Lower colour grades have yellow and brown tints which are undesirable in colourless diamonds. However, these diamonds cannot be classified as coloured diamonds. Only stones with an intense tone (deeper than grade Z) and a richer, more glowing hue are categorised as coloured or fancy diamonds. The name ‘fancy’ is used in the sense of ‘unusual’ or ‘special’ ‒ a very apt description, because coloured diamonds are far rarer than their colourless cousins and are also extremely impressive thanks to their extensive range of hues.
Let‘ s take a closer look at the characteristics of the various colours and how they are created.
Yellow, Orange and Brown
These shades are created by nitrogen deposits in the crystalline matrix of the diamond during its formation. Yellow diamonds are among the commonest coloured diamonds. In this colour category, intense canary yellow is regarded as the rarest hue. Pure, clear orange is also extremely rare because it is a blend of red and yellow and the clarity of the orange hue is often impaired by irregular colour gradations. The various hues found in brown diamonds are often described as ‘champagne’, ‘cognac’ or ‘chocolate’. These coloured diamonds are created by changes to the gemstone's crystalline structure, causing variations in light absorption.
Traces of boron are responsible for the colour blue in diamonds. The higher the concentration, the more intense the colour; however, no diamonds of a blue as deep and rich as that of sapphires have ever been found. Blue diamonds occur in hues of blue, grey-blue, greenish-blue, turquoise and aquamarine. Diamonds in greyish-blue ‒ caused by the presence of hydrogen ‒ are especially rare. Turquoise and aquamarine diamonds have a particularly high sparkle, resulting from changes to their crystalline structure caused by natural radiation.
Pink, Lilac and some Brown diamonds
These colours are created by pressure which deforms the stones‘ crystalline matrix. Pink diamonds are especially rare, generally occurring ‒ if at all ‒ at low carat weights; they are seldom found in a pure, clear shade of pink. Lilac diamonds are often confused with violet stones. They frequently have a greyish or pinkish hue. Pure lilac is extremely rare, as it is a blended colour.
Coloured (fancy) diamonds in clear shades of red free from pink, orange or brown gradations are the rarest coloured diamonds, and thus also the most.
In diamonds, the colour violet is caused by the presence of hydrogen. These stones belong to the same family as lilac diamonds and are thus not pure shades.
Green diamonds are created by the action of gamma radiation on the atoms of the stone‘ s crystal matrix. Green diamonds are the second rarest type of coloured diamond. Pure green diamonds can command top prices as fancy diamonds.
Grey diamonds are extremely rare coloured diamonds. In its purest form, their blend of black and white is extremely close to a colourless diamond. Grey often occurs as a secondary colour (greyish blue, greyish green).
Chameleon diamonds are available in shades of grey, yellow, olive, orange and green. They have the unique feature of changing colour in different lights or temperatures. This property is attributed to the extremely high content of hydrogen in the stone.
Black diamonds, although not transparent, have an extremely dramatic appearance. They are believed to be created by inclusions of graphite and carbon; a further theory suggests that the diamonds once fell to earth as meteorites. The inclusions in black diamonds, which may frequently be white and grey, are extremely porous and the stones are therefore extremely complex to cut for the jewellery industry.
White diamonds must not be confused with colourless, clear diamonds. Unlike transparent, colourless diamonds, white diamonds are milky and may include brown, blue, yellow or grey tints.
Coloured diamonds - Description and classification
Descriptions of coloured diamonds classify their hue, tone, saturation and colour dispersion.
The hue describes the main colour of the gem, and is the final term to be listed in what may sometimes be a very long description.
The tone of a coloured diamond indicates how pale or dark the gem is. This depends on the level of brown, black, grey or white in the stone.
Saturation is used to grade the intensity of the colour. Descriptions use the terms ‘fancy light’ and ‘fancy intense’ for diamonds with light hues, while dark diamonds are described as ‘fancy dark’ and ‘fancy deep’.
The colour dispersion indicates the evenness of colour distribution throughout the gem.
Even though colour identification is subject to strict criteria, it is extremely difficult to pinpoint a colour. Certification is conducted by institutes including the GIA, IGI and HRD, which use reference diamonds to give exact classifications. The more precise and detailed the description of a coloured diamond is, the better. Using a single word to describe the colour of a fancy diamond not only fails to enhance the value of the stone, but may even be regarded as incorrect. Descriptions therefore often comprise lengthy strings of adjectives such as ‘fancy deep brownish greenish yellow’, with the last word always indicating the main hue.
As with colourless diamonds, coloured diamonds are graded by scales of clarity, cut, shape and carat. However, clarity is not such a vital criterion for determining the value of a coloured diamond as it is for colourless diamonds, because inclusions need not impair the quality and brilliance of the colour. The most popular cuts are ‘fancy cuts’ such as radiant and cushion cuts, followed by oval, pear, heart and marquise cuts. Carats (weight) are graded in the same way as for colourless diamonds. However, apart from these criteria the colour and beauty of a fancy diamond are the main factors determining its value.
The most famous coloured (fancy) diamonds
Coloured diamonds are particularly valuable and unique stones. But even these rare gems include some very special diamonds which have become especially famous for their size, colour or rich history.
he huge 128.51-carat Tiffany Diamond, in a beautiful shade of golden yellow, was naturally famous for its size, but also for its prestigious purchaser - the owner of Tiffany & Co. - and appeared in the spotlight around the neck of actress Audrey Hepburn for the film ‘Breakfast at Tiffany's’.
A further world-famous diamond is the Hope Diamond. This stone changed owners extremely frequently, passing in the course of its long history through hands including King Louis XIV and the London banker Thomas Hope, who gave it its name. The Hope Diamond plays an important part in the film ‘Titanic’ ‒ but it is also unique for its appearance, an especially rich, deep blue.
You can explore more famous coloured diamonds in our Diamond Dictionary.