550 carat Emerald and Diamond Tiara to be autioned at Sotheby's

Regarded as one of the most important magnificent Noble Jewels auction by Sotheby's in 30 years, this rare Emerald and Diamond tiara will be auctioned by the house on May 17, 2011.

The Tiara which contains 11 Colombian Emeralds and is estimated to bring around $5-10 million.

It is believed that the tiara was commissioned sometime during 1900, possibly from the renowned jewelers Chaumet, by Guido Count von Henckel, First Prince von Donnersmarck, for his second wife Princess Katharina.

The exceptionally rare 11 pear-shaped Columbian emeralds weigh over 550 carats and may well have been one of the most precious pieces in the Donnersmarck collection.

The jewelry collection of the Royal family was known to be on a par with, or even to have exceeded, those of many of the crowned heads of Europe.