This is an authentic TIFFANY 18K Yellow Gold Diamond 1837 Circle Pendant Necklace. This one-of-a-kind necklace features a circular 18 karat gold pendant with a single diamond in the center. This is a marvelous necklace for a distinctive look from Tiffany & Co.! Follow this item for alerts. Tiffany is a registered trademark of Tiffany. FASHIONPHILE is not affiliated with Tiffany.