Lady Gaga was attending Harper's Bazaar celebrates icons by Carine Roitfeld party held during New York fashion week on September 5, at the Plaza Hotel in the New York City. She was stunning in a custom Alexandre Vauthier Couture outfit and piece-unique Jacob & Co: diamond necklace and 27 ct. round brilliant diamond solitaire ring.  The breathtaking necklace consists of pear shape and round cut diamonds, totaling 58.84 cts, exquisitely set in platinum. The diamond solitaire ring, from the high jewelry collection, features a 27ct round brilliant cut diamond center, also set in platinum.