At AC Silver, we know that every diamond is unique and special in its own way. They come in a spectrum of dazzling colours and if you haven’t already guessed, we’re pretty obsessed with them! Most of our customers tend to associate diamonds solely with the colourless, glistening variety. However, there’s much more to the diamond family than you might have realised.


Today, we’re taking a trip through the rainbow of diamond jewellery and finding out a bit more about fancy colour diamonds. Read on to learn all about these multi-coloured gems that are full of surprises.


What are fancy coloured diamonds?


The normal range of colours spans from D-Z on the colour-grading scale. Diamonds that fit into this scale are the ones that you’d recognise – from colourless gems through to gems with a light-yellow tone. However, there are plenty more diamond colours out there, and they’re known as “fancy colour diamonds”.


Any diamond with a colour grade outside of the D to Z range can be considered a fancy colour diamond. Such gemstones are rarer to come across than the classic diamonds, and so they are highly converted – not to mention stunning! Blue, green, pink and red coloured diamonds are particularly sought after, and the stronger and purer the colour is, the more valuable the diamond is likely to be.


How are fancy colour diamonds formed?


True fancy colour diamonds are naturally formed and mined in the same way as typical diamonds. However, they are extremely rare to encounter. Only around 1 in 10,000 diamonds has a fancy colour, which is one of the reasons why natural fancy colour diamonds are so valuable.


There are also numerous ways to synthetically colour diamonds and make them appear to have a fancy colour. Surfacing coating, HTHP (High Temperature/High Pressure) treatment, and Irradiation can all be used to inject colour into a clear gemstone. However, chemically treated diamonds won’t fetch nearly as high a price tag as naturally occurring specimens.


Which colour diamond is the rarest?


The rarest fancy colour diamonds purple, red, orange. So, any piece of jewellery featuring these stunning gems is sure to fetch a large sum. On the other end of the scale, we have yellow and brown fancy colour diamonds. While still beautiful, these colours are slightly more common and therefore less valuable than the impressive bright tones.


Are coloured diamonds worth more?


Like with other types of diamond, the price of fancy colour diamonds varies based on many factors. The rarest colours (purple, red, and orange) are generally considered to be the most valuable, but prices can also vary greatly within each colour range. While typical diamonds are considered to be less valuable if their colour is obvious to the naked eye (with colourless diamonds generally fetching the biggest price tag), the rules are reversed for fancy colour diamonds. With coloured diamonds, the brighter and more obvious the colour, the more valuable the stone. This is because it’s extremely rare to find a large diamond with a naturally occurring vivid colour. Muted coloured fancy diamonds are also impressive, but the general rule is the brighter the better.


How are fancy colour diamonds graded?


The way in which fancy colour diamonds are graded is slightly different to what we’re used to with classic diamonds. These colourful gems are graded along three different axes: hue, tone, and saturation. The hue can be described as the actual colour of the stone – for example, red, blue, or green – whereas the tone represents the lightness or darkness of the colour and the saturation refers to how strong or weak the colour is. The hue of fancy colour diamonds is often described using two different colours, for example, ‘orangey-brown.’


Famous fancy colour diamonds


Because of their rarity, large fancy colour diamonds can be extremely valuable and even become famous. The Pink Star Diamond is one example of a wildly famous fancy colour diamond. This stunning, pink-hued gemstone is simply mesmerising and it fetched an incredible $71.2 million when it was sold by Sotheby’s in Hong Kong.


Another high-profile fancy colour diamond is the Hope Diamond. This gorgeous blue-toned diamond is incredibly valuable and famous. It was even believed to be the inspiration for the Heart of the Ocean necklace in the Titanic film. This unrivalled diamond is one of the most famous gemstones in the world, with an estimated price tag of between $200 and $350 million.


what are fancy coloured diamonds
350z33, CC BY-SA 3.0, via Wikimedia Commons

Fancy colour diamonds stand out from other gemstones. Their rarity and bold colour make them extremely exciting and sought after. It’s true that diamonds are the gift that keeps on giving – whether you’re looking for a subtle sparkle or a show-stopping pop of colour, there’s sure to be a perfect diamond out there for you!


Written by

Delilah Kealy-Roberts

Delilah joined the AC Silver team as a Sales & Digital Assistant in 2017 after completing her degree in English Literature at Leeds University. Delilah possesses a passion for jewellery and antiquities combined with an interest in blogging and social media.