What Drives Fancy Colour Diamond Prices? Colour, Intensity, Rarity and Origin

What drives fancy colour diamond prices?

A fancy colour diamond is a natural or laboratory-grown diamond whose colour is strong enough, or unusual enough, to sit outside the normal D-to-Z scale used for white diamonds. Yellow, brown, pink, blue, green, orange, purple, red, grey and black all qualify. Our complete guide to fancy colour diamonds introduces each colour; this page focuses on why they cost what they cost.

With a white diamond, value comes from the absence of colour, plus cut and clarity. With a fancy colour diamond the logic flips: colour carries most of the value, and clarity matters far less. In rough order of importance, the price depends on:

• Hue: the colour itself. Red, blue, green and pink sit at the top; yellow and brown at the bottom.
• Intensity: how strong and saturated the colour is, from Faint to Fancy Vivid.
• Origin: whether the colour is natural and untreated, natural but treated, or the diamond is lab-grown.
• Purity of colour: whether a secondary colour (a modifier) helps or hurts, for example purplish pink versus brownish pink.
• Carat weight: large fancy colours are much rarer than small ones, so price per carat climbs steeply with size.
• Cut and shape: how well the cutter concentrated the colour face-up.
• Clarity: usually the least important, as long as inclusions do not affect durability or look.

Any unfamiliar word on this page, from hue to saturation, is also defined in our plain-English jewellery glossary.

What causes colour in a diamond, and why are some colours rarer?

Pure diamond is just carbon atoms locked in a tight crystal lattice, and it is colourless. Colour appears when something interrupts that lattice: a trace element such as nitrogen or boron, a distortion of the crystal, or natural radiation. How often each of those things happens in the earth is what sets rarity, and rarity is the foundation of price.

Diamond type is a scientific classification based on nitrogen and boron content. About 98% of natural diamonds are Type Ia. Type IIb diamonds, which contain boron and can be blue, are a tiny fraction of production, which is one reason natural blues are so costly. A gemmological lab can test a stone's type, and that test is a key part of deciding whether its colour is natural.

Some colours are easy to confuse with something cheaper. Salt-and-pepper diamonds, for example, are grey-white stones full of black and white inclusions. They are popular and affordable, but their look comes from inclusions rather than body colour, so they are priced on character rather than on the fancy colour scale.

How do intensity grades from Faint to Fancy Vivid change the price?

GIA describes fancy colour using three things: hue (the colour), tone (how light or dark it is) and saturation (how strong or pure it is). These are combined into one of nine intensity grades. Our guide to how labs grade fancy colour diamonds explains the viewing conditions and colour comparison stones used.

The jump between grades is not small. For natural yellows, a Fancy Intense stone often costs noticeably more than a Fancy, and a Fancy Vivid can cost two to three times a Fancy Intense of the same size. For pinks and blues the gaps are wider again. The full ladder is set out in our step-by-step intensity scale from Faint to Vivid, and the top grade gets its own page on what earns a Fancy Vivid grade.

It helps to see where white diamonds end and fancy yellows begin. On the D-to-Z colour grading scale, a colourless E grade or F colour diamond is valued because it shows almost nothing. By the time you reach an H colour stone, an I colour diamond or a J colour diamond with its gentle warmth, the tint is visible and the price falls. Keep going past Z and the colour becomes the point again: a yellow stronger than Z is graded Fancy Light Yellow, and the price starts to rise.

Why do hue and modifiers matter so much to a coloured diamond's price?

Most fancy colour diamonds are not a single pure colour. The grade names the main hue last and any secondary colour, called a modifier, before it. A Fancy Intense purplish pink is mainly pink with a purple influence; a Fancy Intense pinkish purple is mainly purple. The order of words changes the stone, and usually the price.

• Modifiers that usually add value: purplish in pink, orangy in yellow (for some buyers), greenish in blue when the result is a clean, bright colour.
• Modifiers that usually reduce value: brownish and greyish in almost any hue, because they dull the colour.
• Pure colours: a 'Fancy Vivid Pink' or 'Fancy Vivid Blue' with no modifier commands the highest premium of its hue.

Two diamonds with the same intensity can therefore sit a long way apart on price. A Fancy brownish pink may cost a fraction of a Fancy pink, and a greyish blue less than a pure blue. Our page on how modifiers and overtones shift colour and value lists the common combinations and how the market treats each one.

Why are Argyle pink diamonds so expensive?

Australia has a special place in the fancy colour story. The Argyle mine in the east Kimberley region of Western Australia, operated by Rio Tinto, produced diamonds from the mid-1980s until it closed in November 2020. Most of its output by volume was brown, but it is famous for producing about 90% of the world's pink diamonds, along with a small number of reds, violets and blues.

Even at Argyle, pinks were a tiny fraction of one per cent of production. The most important stones were sold each year through the invitation-only Argyle Pink Diamonds Tender. Argyle also used its own colour language: a number for intensity (with 1 the most intense) and letters for hue, such as P for pink, PP for purplish pink, PR for pink rose and PC for pink champagne. For browns, Argyle promoted a champagne-to-cognac scale running from C1 (lightest) to C7 (darkest), which is why Australians often say 'champagne diamond'.

• Fixed supply: with the mine closed, no new Argyle rough is being produced, so the number of genuine Argyle pinks is finite.
• Paperwork: certified Argyle pinks usually carry an Argyle certificate and a laser-inscribed number on the girdle (the thin edge of the stone). Check that the inscription matches the certificate.
• Small sizes: most Argyle pinks are under 0.50 carat; a pink over 1 carat is exceptional.
• A note on value: prices for Argyle pinks have risen over the years, but past prices are no guide to future resale. A coloured diamond is something to wear and enjoy, not a financial product.

Argyle champagne and cognac diamonds sit at the opposite end of the market: natural, Australian and attractive, but far more plentiful, which keeps them affordable.

How do natural, treated and lab-grown fancy colour diamond prices compare?

Origin is the single biggest price switch after hue. The same pink can be natural, a natural diamond with treated colour, or a lab-grown diamond. To the eye they can look alike, which is why an independent report matters. On a GIA coloured diamond report, look for the colour origin line. Here is how it reads in practice:

• 'Fancy Intense Yellow' with colour origin 'Natural': a mined diamond whose colour formed in the earth, untreated. This is the top price tier for that hue and grade.
• 'Fancy Deep Blue' with colour origin 'Treated': a natural diamond whose colour was created or changed by a lab process such as irradiation or HPHT (high pressure, high temperature) treatment. The comments section often names the process. It is real diamond, priced at a small fraction of a natural blue.
• Colour origin 'Undetermined': the lab could not confirm whether the colour is natural. The market usually prices this cautiously, closer to a treated stone.
• A GIA laboratory-grown diamond report: a separate report type for lab-grown stones. It states the diamond is laboratory-grown, notes the growth method (CVD or HPHT) and any post-growth treatment, and the girdle is usually laser-inscribed to say so.

Lab-grown fancy colours are physically and chemically diamond, with the same hardness and a refractive index of about 2.42, but they are produced to order, so they cost far less and are easy to find in larger sizes and brighter grades. Blue lab-grown diamonds get their colour from boron added during growth; many lab pinks are coloured after growth. Our guide to laboratory-grown fancy colour diamonds covers each colour, and the forces behind lab-grown diamond pricing explains why those prices keep moving.

How do cut, carat and clarity affect fancy colour diamond prices?

Carat weight matters more for fancy colours than for white diamonds. Colour also looks stronger in a larger stone, because light travels further through it. A 0.20 carat pink can look paler than a 1 carat pink of the same body colour, and large natural pinks and blues are so rare that price per carat can multiply between half a carat and one carat.

Cut works differently, too. With white diamonds, the round brilliant is cut for maximum brightness and carries the highest price per carat. With fancy colours, cutters usually choose shapes that concentrate colour, such as the radiant, cushion, oval and pear, because more facets reflecting light back through the stone deepen the face-up colour. A rough crystal that would grade Fancy as a round might reach Fancy Intense as a radiant, which is why so few fancy colour diamonds are rounds.

GIA does not give an overall cut grade to these shapes, so you judge cut by eye: even colour across the face, no large washed-out window in the centre and a pleasing outline. Our guide to judging cut quality in fancy shapes without a GIA cut grade walks through the checks, and why fancy shapes have no single ideal proportion chart explains why numbers alone are not enough.

Clarity usually comes last. SI (slightly included) clarity is common and widely accepted in natural fancy colours, and strong colour tends to hide small inclusions. The exceptions are large feathers (internal cracks) near the edge, which affect durability, and dark inclusions in a light-coloured stone, which can be visible. Fluorescence (a glow under ultraviolet light) is noted on reports; strong blue fluorescence in a yellow can slightly mute its colour in daylight.

Which settings and metals suit fancy colour diamonds?

The metal around a coloured diamond reflects into it and changes how strong the colour looks. A sensible setting can make a Fancy stone look closer to Fancy Intense; the wrong one can wash it out.

• Yellow diamonds: yellow gold claws or a yellow gold cup under the stone deepen the colour, even on a white gold or platinum band.
• Pink diamonds: rose gold warms and supports pink; white gold or platinum keeps a cooler, purer look. Avoid yellow gold claws on pale pinks, which can push them towards peach.
• Blue and green diamonds: white gold or platinum keeps the colour clean.
• Champagne and cognac: rose and yellow gold suit their warmth.
• Black diamonds: white gold for contrast, or yellow and rose gold for a softer look; bezel or claw settings both work.
• Halos: a halo of white diamonds frames the colour and makes a small centre look larger; a halo of matching coloured diamonds lifts the overall colour.

If your coloured diamond has treated colour, tell your jeweller before any resizing or repair, because heat from a torch can change some treatments. This is one of the reasons the report should travel with the ring.

How do you compare fancy colour diamonds before you buy?

Because so many factors move the price, compare stones in the same order the market prices them:

1. Confirm the origin first. Check the report for colour origin (natural, treated or undetermined) or a laboratory-grown report. Compare natural with natural and lab-grown with lab-grown.
2. Read the full colour grade. Note the intensity and the main hue (the last word), then any modifiers, especially brownish or greyish.
3. Look at the stone in more than one light. Daylight, cool white and warm indoor light all show colour differently.
4. Check colour evenness. Look face-up for patches or a pale centre, and watch a 360° video if you are viewing online.
5. Compare size in millimetres. Deep-cut coloured stones can carry hidden weight; a shallower stone of the same carat can look larger.
6. Plan the metal. Decide whether yellow, rose or white metal will support the colour, and look at real fancy coloured engagement ring designs before committing to a stone.