The Fortune Pink, an exceptionally rare giant gemstone, will be auctioned in Geneva in November when it is expected to go for up to $35 million (36 million euros), auctioneers said Monday.
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.
The sparkling pink tear-drop-formed stone, which has been mounted on a ring flanked by a large white diamond on either side, weighs exactly 18.18 carats.
Christie's highlighted that this was considered a lucky number in Asia, where it signifies "definite prosperity", saying it expected the diamond to "garner interest from collectors across the globe."
"Weighing in at an auspicious 18.18 carats... the weight in fact brings luck to the new owner," Angela Berden, Christie's senior jewellery specialist, told AFP.
"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."
While the Fortune Pink is the largest vivid pink pear-shaped diamond to go to auction, larger cushion-shaped pink diamonds have previously gone under the hammer.
In 2018, Christie's sold the 18.96-carat Winston Pink Legacy, which raked in over $50 million -- the highest per-carat price ever paid for a stone of its kind.
The giant Raj Pink diamond, weighing a full 37.3 carats, meanwhile, failed to sell at a Sotheby's auction a year earlier, where it had been estimated at up to $30 million.