Sancy Hope diamond. The Sancy was in the collection of Vasiliy Rudanovsky until 1828 when purchased by Prince Demidoff for £80,000. It remained in the Demidov family collection until 1865 when sold to Sir Jamsetjee Jeejeebhoy, an Indian prince, for £100,000. He sold it only a year later, creating another gap in its history. It reappeared in 1867, displayed at the Paris Exposition, carrying a price tag of one million francs; the gem then vanished again for forty years. The Sancy next surfaced in 1906 when bought by William Waldorf Astor, 1st Viscount Astor, from famous Russian collector A.K.Rudanovsky. The prominent
Vickrey auction mainly considered auctions where only a single, indivisible good is being sold. The terms "Vickrey auction" and "second-price sealed-bid auction" are, in this case only, equivalent and used interchangeably. When either a divisible good or multiple identical goods are sold in a single auction, however, these terms are used differently. Vickrey auctions are much studied in economic literature but uncommon in practice. Generalized variants of the Vickrey auction for multiunit auctions exist, such as the generalized second-price auction used in Google's and Yahoo!'s online advertisement programmes (not incentive compatible) and the Vickrey-Clarke-Grove Auction (incentive compatible). In a Vickrey auction with