Ask ten people which diamond colour is rarest and most will say blue or pink. The honest answer is red. Fewer red diamonds have ever been found than any other body colour, and most of the ones that exist are small — often well under a carat. When one comes up for sale it makes headlines, which tells you how thin the supply is.

This guide sets out the order of rarity as the gem trade understands it, explains why some colours are so scarce, and — the part that actually matters when you are shopping — what any of this means for a ring you can realistically buy in the UK.

The rarity order, from scarcest to most common

Rarity here means how often a colour turns up in mined rough, not how expensive a stone looks. The rough ranking below is the one used across the trade. It is a consensus built from decades of auction and mining records, not a measured statistic, so treat it as a reliable guide rather than a precise league table.

Colour	How scarce in nature	What causes it
Red	The rarest of all — a handful of significant stones known worldwide	Distortion of the crystal structure as the diamond grew
Violet	Extremely rare, usually very small stones	Hydrogen trapped in the crystal
Green	Extremely rare in a true, even green	Natural radiation from surrounding rock
Blue	Very rare	Boron atoms in place of carbon
Orange	Very rare in a pure orange with no brown	Nitrogen in a particular arrangement
Pink and purple	Rare, and scarcer since the main source mine closed in 2020	Distortion of the crystal structure
Yellow	The most available of the fancy colours	Nitrogen atoms in place of carbon
Brown	The most common coloured diamond by far	Distortion of the crystal structure

Why red is the rarest

Red and pink diamonds are not coloured by an added element. They get their colour from a physical fault: as the crystal grew under enormous pressure, its atomic lattice was pushed out of shape. Those distorted planes absorb light in a way that reads as pink to the eye.

Red is simply pink taken to an extreme — the same cause, but with the distortion severe enough to produce a saturated red rather than a soft rose. The conditions have to be near perfect, and if they go slightly further the stone comes out brown instead. That narrow window is why reds are counted in dozens rather than thousands.

A colour is only “rare” once it is strong enough

This is the part most articles skip. A faint bluish tint in a diamond is not a blue diamond. Coloured diamonds are graded on how strong and pure the colour is, using a scale that runs from Faint through Fancy Light, Fancy, Fancy Intense and Fancy Vivid, up to Fancy Deep and Fancy Dark.

The rarity — and the price — sits almost entirely in the top few grades. A Fancy Vivid blue and a Faint blue are the same colour family and worlds apart in scarcity. So when you read that blue diamonds are extremely rare, what is meant is that strong, evenly saturated blues are extremely rare.

What this means if you are buying a ring

Here is the plain truth: natural fancy coloured diamonds in the rare colours are collector items. They are bought at auction, priced per stone rather than per carat, and they are not a normal engagement ring purchase for almost anyone. Nothing about that should put you off — it just means the rarity chart above is interesting reading rather than a shopping list.

What you can buy, and what nearly everyone actually wants, is a bright colourless or near-colourless diamond where all the drama comes from cut and sparkle. That is what we make. Every centre stone we set is lab-grown and comes with a free IGI certificate stating its colour grade, so you know exactly what you have.

If a colourless stone is what you are after, a solitaire round cut engagement ring in white gold shows the stone off with nothing competing for attention — £563 at the time of writing. For something with more presence, the hidden halo oval cut engagement ring tucks a ring of small stones under the centre so the main diamond looks larger from above.

Colour you can actually wear, without the auction house

There is a sensible middle path. If you love the idea of a coloured stone, warm metal does a lot of the work for far less money. A yellow or rose gold setting throws a warm cast into the diamond and gives you that soft, vintage colour feeling honestly, without paying for a rare body colour.

The vintage round cut engagement ring in yellow gold is a good example — the warmth comes from the metal, and the diamond stays bright. You can see the full range in our engagement ring collection, or browse by shape if you already know what you want, such as our round cut rings.

We do not stock natural fancy coloured diamonds, and we would rather say so than sell you something dressed up as one. If you have your heart set on a coloured centre stone, talk to us about a bespoke piece — we design at no extra design cost and will tell you honestly what is achievable and what it will cost.

Rarity and price are not the same thing

One last point worth understanding. Rarity sets the ceiling on price, but four other things decide what a coloured stone is worth: how strong the colour is, how pure it is (a pink with a brown undertone is worth far less than a clean pink), how evenly the colour spreads across the stone, and the size. A small stone in a top grade can outprice a large stone in a weak one.

It is the opposite of how colourless diamonds are priced, where less colour means more money. With fancy colours, more colour means more money — as long as it is the right colour.

How a rare colour is actually priced

Colourless diamonds are priced from published trade lists — a stone of a given weight, colour and clarity has a broadly understood value, and jewellers work within a fairly narrow band. Fancy colour diamonds do not work like that at all.

There is no list. Each stone is judged on its own, and two diamonds of identical weight can differ in price by a factor most people would find hard to believe. Four things drive it:

• Saturation — how strong the colour is. Fancy Vivid sits at the top for most colours.
• Purity of hue — a clean pink is worth far more than a brownish pink of the same strength.
• Evenness — colour that sits uniformly across the stone beats colour concentrated in one area.
• Size — rare colours are usually found in small crystals, so weight adds value steeply.

Cut also plays a different role. A colourless diamond is cut to maximise brightness. A coloured one is often cut to deepen and concentrate the colour, which is why so many fancy colour stones are radiant, cushion or oval rather than round brilliant. Round cutting tends to let colour escape.

Where the rare colours came from

Rarity is partly a supply story. Particular mines produced particular colours, and when a mine closes that colour tightens across the whole market. The clearest example is the Argyle mine in Western Australia, which was the principal source of pink diamonds until it ceased production in 2020. Since then, natural pinks have traded on existing stock rather than new supply.

Blue diamonds have long been associated with a small number of sources, and green diamonds with even fewer. None of this affects the diamond in an ordinary engagement ring, but it explains why the rare colours behave more like art at auction than like jewellery.

Common questions

Is a black diamond rare?

Not especially. Black diamonds get their colour from countless dark inclusions rather than from a colouring element, and they are far more available than the true fancy colours. Many black stones on the market have also been treated to deepen the colour, which should always be disclosed.

Are pink diamonds getting rarer?

Supply of natural pinks tightened after the Argyle mine in Western Australia, which was the main source of pink diamonds, stopped production in 2020. Existing stones still trade; new natural supply is much reduced.

Can lab-grown diamonds be made in rare colours?

Yes. Yellow, blue and pink can all be produced in a laboratory, either by adding elements during growth or by treating the stone afterwards. The colour is real diamond colour, and it must be disclosed as laboratory-grown on the certificate. It is nothing like the price of the natural equivalent.

Does a rare colour mean a better diamond?

No. Rarity is about scarcity, not beauty or quality. A well cut colourless diamond with a clean certificate will look brighter and livelier than a poorly cut rare-coloured one.

Which colour is the most popular for engagement rings?

Colourless and near-colourless by a wide margin. The vast majority of engagement rings sold in the UK use white diamonds, and that is where our whole collection sits.

If you would like a hand narrowing things down, have a look through the engagement rings we make by hand in solid gold and platinum, or get in touch and we will walk you through it. Free insured UK delivery and 30-day returns come as standard.