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While white diamonds may be the classic choice, fancy coloured diamonds add a mesmerising touch of uniqueness and personality to your jewellery collection. Whether you seek a bold statement piece or a delicate accent, these exquisite and rare gems are a cherished symbol of eternal love.
In this guide, we explore what fancy colour diamonds are, the key terminology and types, as well as answering our most frequently asked questions.
What is a fancy coloured diamond?
A fancy coloured diamond is a diamond that exhibits intense colour. Whereas white diamonds increase in scarcity and value the closer they are to colourless, fancy coloured increase in scarcity and value with increasing colour saturation.
Not all fancy coloured diamonds are natural; some are treated or enhanced to create or intensify their colour, and some are lab-grown. Natural, untreated fancy coloured diamonds are much rarer and more valuable than their treated or lab-grown counterparts.
The fancy coloured diamond colour grading scale
Fancy Colour Grades
Greater colour saturation is considered desirable and more valuable in fancy coloured diamonds, which are given a colour grade using a different scale to that which is used for white diamonds. The Gemological Institute of America (GIA) grades fancy colour diamonds from "Fancy Light" to "Fancy" to "Intense" to "Vivid" to "Deep", as shown below.
Fancy coloured diamond terminology
Fancy coloured diamonds have their own special terminology related to grading and describing their unique characteristics. Here are some key terms to look out for:
Hue
Hue refers to the dominant colour of the diamond. Fancy coloured diamonds can come in every colour of the spectrum, and the GIA grades them based on 27 different hues.
Tone
Tone refers to a colour's relative lightness or darkness in a fancy coloured diamond.
Saturation
Saturation refers to the strength or intensity of the colour. In general, the higher the saturation, the more valuable the diamond.
Distribution
Distribution refers to how evenly the colour is spread throughout the diamond. It can be either even or uneven.
Secondary colours or overtones
Some diamonds display one dominant colour and one or more secondary colours, also called overtones. For example, a diamond might be described as having a "Fancy Yellowish Green" colour, where green is the dominant hue and yellow is the overtone.
Types of fancy coloured diamonds
Natural vs. Treated vs. Lab-Grown
- Natural fancy coloured diamonds are mined diamonds that get their colour from the natural processes that occurred as they formed over millions or billions of years.
- Treated or enhanced fancy coloured diamonds are mined diamonds that have been subjected to treatments like high temperature or irradiation to create or intensify their colour.
- Lab-grown fancy coloured diamonds are (as the name suggests!) fancy coloured diamonds that have been created in a laboratory.
Fancy yellow diamonds
Fancy yellow diamonds, also known as canary diamonds, are the least rare fancy coloured diamonds in nature. Their colour is caused by the presence of nitrogen atoms within their crystal structure. The trace amounts of nitrogen allow the diamond to absorb blue light, making the diamond appear yellow.
Because they are more common than other fancy colour diamonds like blue or pink, they can be a more affordable option for those seeking a colourful diamond.
Fancy pink diamonds
Fancy pink diamonds are even rarer in nature than fancy yellow diamonds and so even more highly prized. Their colour ranges from a pastel rose, akin to blush pink, to a deep raspberry colour. The most intense and vibrant pinks are the most desirable and command the highest prices.
The cause of the pink colour is not fully understood, but unlike other colours, it is not due to trace elements within the crystal structure. Instead, it results from a process known as plastic deformation. This occurs during the diamond's journey to the surface of the earth, where enormous pressure causes changes in the diamond's crystal lattice that cause these unique diamonds to absorb certain wavelengths of light, producing their pink colour.
Fancy pink diamonds are found in a few mines around the world, but the most significant source has been the Argyle mine in Australia. However, the Argyle mine ceased operations in 2020, which has led to speculation that the already rare pink diamonds could become even more scarce and valuable.
Fancy blue diamonds
Even rarer in nature than their fancy pink counterparts, fancy blue diamonds are among the rarest and most coveted coloured diamonds in the world. Their unique colour is the result of boron atoms in the carbon lattice of the diamond. Boron absorbs light in the red, orange, and yellow wavelength range, reflecting the blue wavelength and thus giving the diamond its blue colour.
Blue diamonds are primarily found in three mines: the Cullinan Mine in South Africa, the Golconda Mine in India, and the Argyle Mine in Australia. However, they are still exceedingly rare; for every 10,000 white diamonds mined at the Cullinan Mine, only one natural blue diamond will be found.
Fancy red diamonds
Fancy red diamonds are the rarest of all coloured diamonds. They are so rare that only a handful of true red diamonds are known to exist, and most are less than half a carat in size.
Unlike other fancy coloured diamonds, fancy red diamonds exist in only one colour intensity (anything less intense is fancy pink). Red diamonds with no secondary hues like purple or brown are the rarest and most valuable.
Like fancy pink diamonds, the colour of fancy red diamonds is not due to the presence of trace elements in the crystal structure but instead results from plastic deformation.
Due to their extreme rarity, red diamonds are incredibly valuable and often considered priceless. They are rarely seen on the market, and when they do appear, they are typically the highlight of the auction, attracting attention from collectors and investors around the globe.
Fancy purple diamonds
Fancy purple diamonds are a unique and rare type of coloured diamond. Their colour ranges from light lavender shades to deep, rich purples. The exact cause of the purple colour in diamonds isn't fully understood, but it's generally believed to be related to high levels of hydrogen and boron in the diamond's structure.
Pure purple diamonds, with no secondary hues, are exceptionally rare and highly valuable. Most purple diamonds on the market are smaller in size, often less than 2ct, due to the rarity of this colour.
Fancy purple diamonds are mainly found in the Argyle mine in Australia, also known for producing most of the world's pink diamonds. With the Argyle mine's closure in 2020, the already rare fancy purple diamonds may become even more scarce, potentially increasing their value in the future.
Fancy green diamonds
Fancy green diamonds are unique and beautiful coloured diamonds ranging from light, minty hues to intense, deep greens. The green colour in these diamonds is often due to natural radiation exposure over thousands of years, which alters the diamond's crystal lattice and allows it to absorb red and yellow light, reflecting a green hue.
Green diamonds can also exhibit secondary hues, like blue, yellow, or grey, which can affect their value. A pure green diamond with no secondary hues is very rare.
One thing to note is that there are also green diamonds on the market that have been treated or enhanced to create or intensify their green colour. These diamonds typically have been exposed to radiation in a laboratory setting. While beautiful, they are less rare or valuable than natural fancy green diamonds.
Fancy orange diamonds
Fancy orange diamonds display a range of shades from light to dark orange, and their colour is usually caused by the presence of nitrogen and structural anomalies in the diamond’s crystal lattice.
Pure, intense orange diamonds are among the rarest diamonds in nature, and when these diamonds are found, they are usually relatively small, often less than 1ct.
Black diamonds
Black diamonds are not typically classified as ‘fancy coloured’ because they are opaque and do not exhibit the same colour saturation as other fancy coloured diamonds. They are graded differently from other fancy coloured diamonds, which are judged on the intensity of their colour. Instead, black diamonds are valued for their unique lustre and finish, which gives them a metallic and shiny appearance. The colour is not caused by impurities like in other coloured diamonds. Instead, the colour comes from the diamond's unique structure, which consists of millions of diamond crystals and affects how it absorbs light.
Natural black diamonds can be found in alluvial deposits (soil in riverbeds, valleys, and shorelines) and are believed to have originated from space more than 3.8 billion years ago. The two largest deposits of black diamonds are found in Brazil and the Central African Republic.
It's important to note that there are also treated black diamonds on the market. Natural black diamonds are more valuable and desirable than these treated stones.
Shapes of fancy coloured diamonds
Fancy coloured diamonds can be cut to any shape, but certain cuts display colour more intensely, making them particularly popular for fancy coloured diamonds. These include:
Radiant Cut
Radiant cut diamonds are rectangular or square-shaped with trimmed corners (strictly speaking, octagonal). The radiant cut features a brilliant-cut pattern with numerous facets allowing maximum light reflection. The radiant cut is very popular for fancy coloured diamonds because it enhances the colour saturation and brilliance.
Cushion Cut
Cushion cut diamonds are square or rectangular cut with rounded corners, resembling a pillow shape. The cushion cut has large facets that enhance the diamond's colour and brilliance. The cushion cut is often chosen for fancy coloured diamonds because it showcases their colour intensity and provides a vintage and romantic appeal.
Oval Cut
Oval cut diamonds are often favoured for fancy coloured stones as the oval cut intensifies the colour while also maximising the apparent size of the stone with a timeless and elegant appeal.
The value of fancy colour diamonds
Many of the world's most valuable diamonds are fancy coloured stones, but as with all diamonds, the value of a fancy colour diamond depends on its size (measured in terms of its carat weight) and its quality (assessed in terms of its colour, clarity, and cut) and whether it is natural, untreated, treated, or lab-grown. The most valuable fancy colour diamonds measured on a cost-per-carat basis are natural, untreated fancy reds.
FAQs
What is the rarest fancy coloured diamond?
Red diamonds are considered the rarest of all fancy coloured diamonds. They are so rare that only a small number of true red diamonds are known to exist, and they are seldom seen on the market.
The most famous red diamond is the Moussaieff Red Diamond, formerly known as the Red Shield Diamond. This triangular cut diamond weighs 5.11ct and is the largest red diamond in the world. It was discovered in the 1990s in Brazil and was purchased by Moussaieff Jewellers Ltd. in the early 2000s.
Are coloured diamonds more expensive?
The price of coloured diamonds, also known as fancy coloured diamonds, can vary greatly depending on the specific colour, intensity, carat, and overall quality of the diamond. Some coloured diamonds are more expensive than their colourless counterparts, while others may be less expensive.
Among the coloured diamonds, red, blue, and pink are considered the rarest and are generally the most expensive. These diamonds, particularly when they display a deep, rich colour and have few inclusions, can command higher prices per carat than even the most flawless colourless diamonds.
It's also important to note natural coloured diamonds are significantly more valuable than those that have been treated or lab-grown.
What is the cheapest fancy coloured diamond?
Among fancy coloured diamonds, brown and yellow diamonds are generally more common and less expensive than other vivid and intense coloured diamonds. This is due to their abundance in the market and the fact that they are not as rare as other colours like blue, pink, or red.
Are coloured diamonds natural?
Coloured diamonds do occur naturally. Natural coloured diamonds are formed under unique geological conditions that cause various trace elements and structural defects to affect the diamond's crystal lattice, resulting in the display of different colours. However, in addition to natural fancy coloured diamonds, there are also treated or enhanced fancy coloured diamonds on the market, as well as lab grown fancy coloured diamonds.
Summary
Fancy coloured diamonds are exceptional gems that boast vivid and intense colours, from mesmerising yellows and pinks to blues, greens, and reds.
Fancy coloured diamonds derive their hues from trace elements within the crystal structure, such as nitrogen for yellows and boron for blues, and also from changes to the crystal structure called plastic deformation in the case of pinks and reds.
The rarity of these diamonds in nature, with only a tiny fraction of the world's production exhibiting vivid colours, adds to their allure and makes them highly sought after by collectors and investors.
Colour hue, tone, saturation and distribution all influence the value of a fancy coloured diamond. The most prized diamonds exhibit strong and pure colours with minimal secondary hues, while size and clarity also contribute to their worth.
If you are interested in learning more about fancy coloured diamonds and have any questions, please feel free to get in touch.
