Important and rare 5.16 carats fancy vivid blue diamond and diamond ring, "De Beers Millennium Jewel 11". Photo Sotheby's

Centring on a pear-shaped fancy vivid blue diamond weighing 5.16 carats, flanked on each side by a shield-shaped diamond, mounted in platinum. Estimate 36,000,000 — 46,000,000 HKD. Lot 1621 sold 49,940,000 HKD

Ring size: 5½

Accompanied by GIA report numbered 1112874424, dated 23 March 2010, stating that the 5.16 carat diamond is natural, Fancy Vivid Blue colour, Internally Flawless clarity, inscribed with "De Beers Millennium Jewel 11". 

Sotheby's. MAGNIFICENT JEWELS & JADEITE, Hong Kong,  07 Apr 2010