Signet Jewelers is starting to shine again. After a decade of ups and downs, the world's largest jewelry retailer is regaining its sparkle on both sides of the Atlantic. Running rings around its smaller competitors, Signet is the largest UK jewelry retailer, with about 540 stores under the H.Samuel, Ernest Jones, and Leslie Davis banners. Signet's Sterling Jewelers subsidiary is #1 in the US (ahead of Zale), with more than 1,300 stores, including 900-plus mostly mall-based shops under the Kay Jewelers name, the off-mall Jared format, and host of other stores under various regional banners. Signet sells gold, silver, diamond, and gemstone jewelry; watches and watch services; collectibles (UK only); and gifts.