Last updated on June 13, 2021
Like with colourless diamonds, the 4 Cs of fancy colour diamonds represent the four main components of the stone: Colour, Clarity, Cut and Carat Weight. However, the grading of fancy diamonds is a complex and specialized process that needs highly trained graders to complete the grading accurately.
What Are Fancy Colour Diamonds?
Diamonds in the normal colour range are colourless, and they are described using the D-to-Z colour-grading scale, where D signifies a completely colourless stone, and Z means an easily noticeable yellow or brown tint. However, the world of diamonds is not limited to this scale. There are rare specimens that come in a variety of colours and shades, which are commonly called “Fancy Colour Diamonds” or simply “Fancy Diamonds”.
While the value of colourless diamonds usually decreases as the colour becomes more noticeable, the opposite happens with fancy colour diamonds. Their price increases with the strength and purity of the primary colour. Not to mention, large, vivid fancy colour diamonds are extremely rare and pricy as a result.
Fancy colour diamonds come in almost any colour one can imagine – white, grey, black, purple, pink, red, orange, brown, yellow, olive, green and blue. However, some colours are more common and less valuable than others.
Colour of Fancy Diamonds
When it comes to fancy colour diamonds, the chief determinant of their value is the colour rarety. Even very slight colour differences can have a big impact on value.
When talking about colourless diamonds, the value is based on the absence of colour, D colour diamonds being the rarest. Just the opposite happens with fancy colour diamonds; their value increases with the strength and purity of the colour.
Fancy diamonds come in almost any colour one can imagine. The most valuable colours are saturated pink, blue and green. Diamonds with red, green and blue medium to dark tones and moderate saturations are extremely rare. In general, diamonds with a noticeable hint of any other hue than yellow and brown are considerably rare.
Diamonds with red or reddish colours, also known as “rose-coloured” diamonds, are extremely rare and highly valued. In this range, pure pinks are more popular than orangy, purplish, greyish or brownish diamonds.
Blue diamonds are extremely rare as well. Their colour is caused by the presence of boron impurities, meaning the more boron, the deeper the blue colour. However, blue diamonds are rarely highly saturated and generally have a slight hint of grey.
Green diamonds are typically light in tone and low in saturation. Their colour is often muted with a greyish and brownish cast. Green stones get their colour when radiation displaces carbon atoms from their normal position in the crystal structure. This can happen naturally when diamonds deposit lies near radioactive rocks or artificially as a result of treatment.
Brown is the most common fancy diamond colour. Brown diamonds range in tone from very light to very dark. They were considered good only for industrial use until the 1980s, when they began to appear in the Argyle mines, Australia. For marketing purposes, the Australians gave them names like “cognac” and “champagne”. Nowadays, brown diamonds are popular in many mid-level jewellery designs.
The second most common fancy diamond colour is yellow. In trade, yellow diamonds are sometimes called “canary” for the same marketing purposes.
Fancy white and grey diamonds also exist. White ones have milky white colour and display beautiful flashes. Greys probably got their colour due to a high level of hydrogen content and are getting popular for vintage style jewellery designs.
Clarity of Fancy Diamonds
The clarity of fancy colour diamonds is graded the same way as that of colourless stones. The fewer inclusions, the higher the clarity grade.
Of course, high clarity fancy diamonds are more valuable, but this characteristic is not crucial for colour diamonds. Gemstones of lower clarity grade are still highly prized if they display attractive face-up colour.
As a general rule, the colour tends to hide imperfections, so the appearance of fancy diamonds is less affected by flaws compared to colourless diamonds. The only factor that can lower the diamond’s value significantly is inclusions that threaten the gem’s durability.
Cut and Carat Weight of Fancy Diamonds
Unlike colourless diamonds, fancy colour diamonds are not cut to maximize brilliance and sparkle. Fancy colour diamonds are cut to achieve the best colour possible. In other words, the proportions that are considered ideal for colourless diamonds will not always be the best to bring out the colour of fancy diamonds.
So when choosing a fancy diamond, you should focus more on the stone’s colour intensity and hues, rather than judge the diamond using traditional cut grades.
Larger fancy colour diamonds are rarer and more valuable than smaller ones, which is also true for colourless diamonds. However, cut and size can greatly affect the colour of a fancy diamond. The larger the diamond, or the deeper the pavilion, the richer and more intense the colour.
The style of the cut can influence colour intensity as well. For example, there are certain cut styles (typically mixed cuts) that intensify the yellow colour in diamonds.