A stunning pink diamond described as one of the world's purest and is expected to sell for more than $21 million has arrived in Dubai for public viewing

The Williamson Pink Star, an 11.5-carat stone was unveiled on Monday by Sotheby's Dubai at the Dubai Diamond Exchange, ahead of a tour to Singapore, Taipei and Hong Kong, where it will be offered in a standalone, single-lot auction on October 5.

Dubbed as a "natural wonder of nature", the cushion-shaped gem is the second largest internally flawless fancy vivid pink diamond to ever appear at an auction. It is outsized only by CTF Pink Star, a 59.60-carat oval mixed-cut diamond that was sold at Sotheby's for $71.2 million in April 2017.

The diamond will be available for public viewing at the Monogram Room of Four Seasons DIFC tomorrow, September 6.

Sotheby's said the diamond is expected to fetch $21 million at the auction in Hong Kong next month.

"The discovery of a gem-quality pink diamond of any size is an extremely rare occurrence. Driven by a limited supply and rising demand, prices for top-quality large pink diamonds over 5 carats have increased exponentially over the past de cade, serendipitously setting the scene for the appearance now of this one-of-a-kind stone, said Wenhao Yu, Chairman of Jewellery and Watches at Sotheby's Asia.

(Reporting by Cleofe Maceda; editing by Seban Scaria)

cleofe.maceda@lseg.com