This is an authentic ROBERTO COIN 18K Yellow Gold Diamond .25ct Diamonds By The Inch Necklace. The necklace is crafted of 18 karat yellow gold and features a bezel-set round brilliant cut diamond, approximately .25 carat, with F color and SI2 clarity, with a synthetic ruby on the back side. Follow this item for alerts. Roberto Coin is a registered trademark of Roberto Coin. FASHIONPHILE is not affiliated with Roberto Coin.