Elsa Peretti is one of only four designers permitted to sign their names to the famed jewelry company’s pieces. Known for her sensual, fluid designs, the bone cuff is among the most renowned, and this latest incarnation is my absolute favorite. It literally looks like liquid gunmetal gray, poured onto the wrist and sexy as hell. In ruthenium over copper, this classic piece can be yours for $400 at Tiffany.