COMINGS AND GOINGSJames N. Fernandez>>?James N. Fernandez, a 30-year Tiffany & Co. veteran who currently serves as both chief operating officer and chief financial officer, will retire in July. Ralph Nicoletti will replace him, and fill the roles of executive vice president and CFO. Nicoletti joins the company from insurer CIGNA, where he also served as executive vice president and CFO.>>?Charles D. “Chuck” Lein has told Charles & Colvard he is retiring and will not run for reelection to the company’s board, the moissanite manufacturer announced. He will ­continue to serve on the board until this month.Vince Marchetta>>?Akron, Ohio–based Sterling Jewelers has promoted both Vince Marchetta and David Jacobsen to the positions of vice president of real estate. Marchetta will be responsible for Sterling’s real estate port­folio for the western portion of