GENEVA. David Bennett, Sotheby’s Chairman of Jewellery for Europe and the Middle East, today announced that Sotheby’s will sell the most valuable emerald and diamond Tiara to have appeared at auction in over 30 years in its sale of Magnificent and Noble Jewels in Geneva on the 17th May 2011. Estimated to sell for £3.1-6.2 million (CHF 4.5- 9 million / $5-10 million), the Highly Important and Extremely Rare Emerald and Diamond Tiara is composed of 11 exceptionally rare Colombian emerald pear-shaped drops which weigh over 500 carats in total, which may well have originally adorned the neck of a Maharajah. These emeralds are also believed to have been in the personal collection of Empress Eugénie. This tiara was commissioned, possibly from the renowned jewelers Chaumet, by Guido Count von Henckel, First Prince von Donnersmarck for his second wife Princess Katharina (1862-1929). The jewellery collection of the Donnersmarcks was known to be on a par with, or even to have exceeded, those of many of the crowned heads of Europe.