Legendary jewelry firm J.E. Caldwell & Co., founded in Philadelphia in 1839 by metalsmith James Emmott Caldwell, built its name on designs created in the fluid Art Nouveau style. But its Art Deco offerings—of which this platinum and ruby ring is a spectacular example—were equally stunning. The ring, which sold at Sotheby’s Feb. 7 Important Jewels auction for $290,500 ($90,500 over its high estimate), features “a very fine unheated Burmese ruby” at its center, says Robin Wright, vice president of Sotheby’s jewelry department. ­Burmese rubies, of course, are scarce in the market, “so when they come up at auction, they tend to sell very well,” says Wright. But stones alone don’t account for the collective desire for this crimson creation. “The exceptional ruby, coupled with the lovely, wearable J.E. Caldwell mounting, inspired a lot of competition among collectors.”