Ten years ago, a fine jeweler wouldn’t have been caught dead selling anything less than 14k gold—so clear were the lines that separated the fine end of the business from its fashionable (but, on the face, less prestigious) counterpart. Then the Great Recession struck, throwing all those hoary distinctions out the window.Alexis Bittar, Erickson Beamon, and Miriam Haskell are among the standouts on the fashion jewelry scene, but they’re far from the only ones. Today, costume jewels—which JCK defines as lines composed of mostly base metals set with either lower-quality natural gems or faux stones like CZ, and often paired with liberal amounts of silver—have become an inventory staple in high-end jewelry stores, offering consumers the size and statement-making potential they crave without breaking the bank.Plus, many retailers are realizing that fashion jewelry is a great way to at