RAPAPORT... A Burmese ruby ring from a private European estate sold formore than 18 times its low estimate, setting a new house record at ChiswickAuctions. An undisclosed buyer purchased the 10.51-carat, natural, unheated stone for GBP 462,500($576,817). The London-based auction house had estimated it would fetch at least GBP 25,000 ($31,179). "Natural rubies above five carats are very rare, and oneover 10 carats is exceptional, so we knew that it might attract a lot ofattention," Sarah Duncan, head of jewelry at Chiswick Auctions, said last week."Rubies of this size infrequently come onto the market, and because of this andits outstanding quality, bidding was, as expected, extremely competitive." Image: The Burmese ruby ring. (Chiswick)