At over 18 carats, the vividly coloured gem is the largest pear-shaped pink diamond of its quality ever to be offered for sale at auction, the Christie's auction house said.
"It's a beautiful stone, it's extremely rare to find a pink diamond, vivid pink diamond, of this size," she said. "The colour saturation of this stone is... so difficult to find in nature, and then when you find a crystal... with that weight, with that colour, and a very good clarity, that's just really rare."
