Of all the gem-quality diamonds that emerge from the ground, less than 1 per cent are anything other than white. Large coloured diamonds are so rare that, through history, they have become famous with their own names and myths, like the supposedly cursed blue Hope or the 128-carat Tiffany yellow.
Deeper colours are rarest, the brightest defined as “vivid” or “intense”. These are always the target of collectors and the grades rise exponentially in value. Colour tones are categorised too, with purer shades worth more.
