This is an authentic ROBERTO COIN 18K Yellow Gold Diamond Tiny Treasures Lock Pendant Necklace. This necklace is crafted of 18 karat yellow gold featuring a lock motif accented with diamonds, weighing approximately .30 total carat weight, along with a hidden synthetic ruby. Follow this item for alerts. Roberto Coin is a registered trademark of Roberto Coin. FASHIONPHILE is not affiliated with Roberto Coin.