Close-up of a yellow gold engagement ring featuring a large round diamond surrounded by smaller diamonds on a pave-set band.

Fancy Coloured Diamonds: Types, Rarity & Value (UK Guide)

A fancy coloured diamond is a natural or lab-grown diamond that exhibits a distinct hue beyond the traditional colourless range. These diamonds get their colour from trace elements or structural anomalies during formation, and their rarity and intensity often make them more valuable.

### What are fancy coloured diamonds?

- Natural vs treated:  Fancy colours occur naturally due to elements like nitrogen (yellow) or boron (blue). Some diamonds are treated to enhance colour, which lowers their value.
- Range of colours:  Diamonds come in hues like yellow, brown, pink, blue, green, purple, red and black. Colour intensity is graded from Faint to Vivid.
- Lab-grown options:  Lab-grown fancy diamonds mimic natural hues but cost significantly less and are more sustainable.

### Types of fancy colours

- Yellow diamonds:  Most common fancy colour; get their colour from nitrogen. Canary yellow stones with intense saturation command higher prices.
- Brown and champagne diamonds:  Affordable and earthy; often marketed as cognac or chocolate diamonds.
- Pink diamonds:  Rare and expensive; mainly found in Australia’s Argyle mine (now closed) and command high prices depending on intensity.
- Blue diamonds:  Rarer still; get their colour from boron. Famous examples include the Hope Diamond. Vivid blue stones can be among the world’s most valuable gems.
- Green diamonds:  Colour caused by natural radiation; extremely rare and typically pale in tone.
- Red and purple diamonds:  The rarest of all fancy colours; usually small and very costly.
- Black diamonds:  Opaque stones with graphite inclusions; often more affordable and popular in avant‑garde jewellery.

### Rarity and value factors

- Colour intensity:  Diamonds with stronger saturation and pure hue (e.g., Fancy Vivid) are more valuable than those with faint or mixed colours.
- Tone and distribution:  Even colour distribution and a pleasing tone increase value; grey or brown secondary tones may lower price.
- Carat weight:  Larger stones are exponentially rarer, especially in vivid colours, which increases their price.
- Origin and provenance:  Pink diamonds from Argyle or blue diamonds from historical mines command premiums.
- Certification:  A grading report from a reputable lab (e.g., GIA) confirms that the colour is natural and helps protect value.

### Tips for buying fancy coloured diamonds

- Buy from reputable jewellers:  Ensure your stone comes with a certificate verifying natural colour and origin.
- Consider lab-grown:  Lab-created fancy diamonds offer vibrant colours at a fraction of the price and are environmentally friendly.
- Balance intensity and budget:  Lower-intensity stones or those with secondary tones are more affordable while still offering unique colour.
- Check fluorescence:  Some fancy coloured diamonds fluoresce; strong fluorescence can affect appearance and value.

### Frequently asked questions

- Are fancy coloured diamonds natural?  Yes—many are naturally coloured, though some stones are colour-treated; certification clarifies this.
- Are lab-grown fancy diamonds real diamonds?  Lab-grown diamonds have the same physical and chemical properties as natural diamonds but are created in a controlled environment.
- Which colours are most expensive? Red, purple and blue diamonds are among the rarest and most expensive; pink diamonds are also highly valuable.
- Can fancy coloured diamonds be used in engagement rings?  Absolutely. They add a unique pop of colour and can be set in complementary metals like rose or yellow gold.

Last updated: March 2026

Back to blog