While JAR (a.k.a. Joel Arthur Rosenthal) may have a shop—and that shop may be in Place Vendôme—there’s no point in swinging by unless he’s accepted your appointment. After all, there isn’t even a sign, much less regular hours. Making only 70-80 pieces per year, this reclusive designer and Harvard grad may have come from humble roots (he’s the child of a biology teacher and Bronx postal worker), but he’s made jewelry for some of the world’s most beautiful women. Those who can’t get an original (he won’t sell a piece to someone unless he’s convinced it’s a match), can always pick something up at auction: A 2006 Christie’s sale of Ellen Barkin’s JAR collection featured 17 pieces, including a 22.76-carat diamond ring that fetched more than 1.8 million.