Women rarely need an excuse to browse a jewelry case, but here’s a new one: Boston’s Museum of Fine Arts inaugurates its permanent jewelry gallery this month with “Jewels, Gems, and Treasures.” Rare for an American fine arts museum, the gallery puts jewelry on par with Picasso, say, or at least Klimt. Among the show’s highlights are Marjorie Merriweather Post’s favorite brooch, made up of diamonds and a 17th-century carved Mughal emerald (left), and purchased, though not worn, for her presentation at the British court in 1929; Betsey Cushing Whitney’s American Indian tiara, worn for her presentation before Queen Elizabeth II in 1956; and Coco Chanel’s cuff, designed by Fulco di Verdura, whose Maltese cross motif Chanel later introduced into her own jewelry collections. Chanel wore the cuff often, as she did several other pieces borrowed from Verdura, preferring to mix both fine and faux. For her, jewelry was less a symbol of wealth than an expression of a woman’s personality. “She set the style for that,” says curator Yvonne Markowitz.