Sotheby's is set to auction a rare 72.22-carat, D-color, pear-shaped diamond - the largest of its kind to date.

The flawless gem will go under the hammer on April 10th at the famous auction house's Hong Kong branch and is expected to sell for between £4.7 million and £6.25 million.

Described as "breathtaking" with a "superb outline", the diamond is prized for its GIA-graded 'Excellent' polish and symmetry in addition to its desirable pear-shape.

Quek Chin Yeow, deputy chairman and head of Jewellery Department, Sotheby's Asia, said: "Asian collectors are amongst the most discerning, and always seeking the best in paintings, works of art and items of rarity on offer.

"Sotheby's Hong Kong is proud to offer one of the most beautiful diamonds available in today's market."

Meanwhile, rival auction house Christie's is planning to auction off a 101-carat near-flawless diamond for approximately £4 million.

Dubbed the largest diamond ever to be put up for auction, it will be the highlight of Christie's spring jewellery sale on May 28th, which is also being held in Hong Kong.