CHANGES AT GRAFF: Graff, the London-based diamond jewelry firm, has reshuffled some of its executive roles. Chief operating officer Colleen Caslin left the company last week when the firm did away with that role. Linda Stark, vice president of wholesale, also exited the firm. Henri Barguirdjian, president and chief executive officer of Graff in America, has taken on some of Caslin’s responsibilities, while other of her tasks will be delegated among Graff staff. The firm also has hired Paul Sterman as senior vice president of wholesale, which is limited to Saks Fifth Avenue in the U.S. Sterman was most recently senior vice president of new account acquisitions at Beaudry, a U.S. diamond jeweler. Graff is set to open a boutique in Bal Harbor, Fla., next month and another in Beverly Hills, Calif., in October. Last month, Graff opened a corporate headquarters in New York and is set to unfurl a new in-store boutique at the Saks Fifth Avenue flagship.