RAPAPORT... An Art Deco Cartier diamond and rock crystal brooch sold for 10 times its high estimate, becoming one of the top five lots ever sold at Chiswick Auctions.The piece was formerly owned by New York socialite Augusta McCagg, a relative of the Vanderbilt family, famous for its shipping and railroad empires. It brought in GBP 150,000 ($212,350) at the May 28 sale after highly competitive bidding, the London-based auction house said last week."This Cartier brooch is a wonderful example of the early influence Indian art had on the jewelry being created by Cartier," said Sarah Duncan, head of jewelry at Chiswick Auctions. "Extensive research into the family history and connections, compounded by the fact that this piece has never before been on the open market, made it very desirable to our international bidders."In total, Chiswick offered 12 of McCagg's jewels, including an Art Deco 3-carat diamond and sapphire ring, which fetched GBP 33,750 ($47,779), smashing its upper estimate of GBP 9,000 ($12,741). Another item from the collection, an early 20th century pocket watch by Tiffany & Co., went for GBP 4,750 ($6,724), more than three times its high valuation.A private collection from a personal friend of celebrated English jeweler Wendy Ramshaw also went under the hammer. Those pieces, which were 100% sold, fetched more than 230% of their combined presale estimate, Chiswick noted.Other notable items included a pear-shaped, 4.10-carat, fancy-yellow diamond ring, which achieved GBP 31,250 ($44,240), and a step-cut, 5.47-carat diamond ring, which garnered GBP 28,750 ($40,700), both well above their high estimates.In total, Chiswick sold 85% of items on offer. The combined value marked the second-best result the auction house has achieved for a jewelry sale, it added.Image: The Cartier brooch. (Chiswick Auctions)