Fancy blue diamonds explained
Coloured by traces of boron and found at only a handful of mines — the rarest and most valuable of the fancy colours.
Blue is the aristocrat of fancy colour. The Hope Diamond is blue; so is much of what comes from South Africa's Cullinan mine, one of the very few sources on earth. For a natural fancy colour diamond buyer, blue is where rarity and value peak.
Boron, and why blue is so rare
A blue diamond is coloured by traces of boron caught in the crystal as it formed. Boron is vanishingly scarce at the depths where diamonds grow, which is why natural blues come from only a handful of mines and appear in fine saturation less often than almost any other colour.
Grade and overtone
Blues run from Fancy Light to Fancy Vivid and Fancy Deep. A grey overtone is common and softens both the colour and the price; a pure, saturated blue with no modifier is the benchmark and the rarest of all. As with every fancy colour, saturation is the single biggest driver of value.
Among the fancy colours, a fine blue is the hardest to replace at any size.
Buying with confidence
Because value is so concentrated, the report matters more here than anywhere: insist on GIA, IGI or HRD, confirm a natural colour origin, and view the stone before deciding.
Explore the Fancy Blue diamonds in our current stock, or tell your relationship manager what you are looking for.
← All primers
