The Diamond Manufacturers and Importers Association plans to hold a gala black-tie dinner Nov. 11 at Cipriani Wall Street in New York to celebrate its 75th anniversary. The event will honor two industry legends—former DMIA president Jacques Roisen and the late William Goldberg. The event will be mostly social, organizers say, and will include music and dancing.

The organization is also opening an office at 580 Fifth Ave.