RAPAPORT... A rare necklace by French jeweler Boivin garnered more than 13 times its high estimate following a fevered bidding war at a recent Fellows auction.The piece, which featured two rows of turquoise beads suspended from a line of rock-crystal beads, fetched GBP 40,832 ($51,574) at the May 26 jewelry sale in Birmingham, UK, blowing away its upper estimate of GBP 3,000 ($3,789). The result came after five minutes of heated bidding from clients on multiple telephone lines, the UK-based auction house said last week."When a piece has no obvious signature, it can be exceptionally difficult to track down the maker," explained Ben Randall, senior specialist and catalogue manager at Fellows Auctioneers. "Dedicated research, style and a hearty dose of luck are necessary. I feel very fortunate that we were able to discover the designer of this necklace. There are certain names that you hope to come across with Art Deco jewelry, and Ren?(C) Boivin is toward the top of a short list. The quality in this necklace really shone through to give a great result."Image: The Boivin necklace. (Fellows)