ELSA PERETTI FOR TIFFANY & CO PLATINUM & .52 CT DIAMOND NECKLACE: .52 CT sparkles as the center piece of this 15.5'' platinum necklace by Elsa Peretti for Tiffany & Co. All the correct markings including Tiffany & Co and Peretti. This necklace currently sells for $500 to $6000 depending on diamond quality and chain length. Est. $3500/6000**