Sancy Astor family possessed it for 72 years until the 4th Viscount Astor sold it to the Louvre for $1 million in 1978. The Sancy now rests in the Apollo Gallery, sharing attention with the likes of the Regent and the Hortensia. Sancy The Sancy, a pale yellow diamond of , was once reputed to have belonged to the Mughals of antiquity, but is more likely of Indian origin owing to its cut, which is unusual by Western standards. The shield-shaped stone comprises two back-to-back crowns (the typical upper half of a stone) but lacks any semblance to a pavilion (the
English auction a Dutch auction would adjust the price in a direction that favored the bidders (lowering the price if the item is being sold to competing buyers, increasing it, if it is a reverse auction). When the auction involves a single item for sale and each participant has as an independent private value for the item auctioned, the expected payment and expected revenues of an English auction is theoretically equivalent to that of the Vickrey auction, and both mechanisms have weakly dominant strategies. Both the Vickrey and English auction, although very different procedurally, award the item to the bidder with the