18K Yellow Gold Emerald and Clustered Diamond Pendant Necklace For Sale Emerald and Diamond Pendant in 18ct Gold Pendants Lockets Jewellery Emerald and Diamond Necklace in 18 Karat Gold at 1stDibs Natural Emerald Pendant 18k Gold With Diamonds Gem. A simple and elegant pendant set with a rectangular emerald measuring approximately 5 3 mm (estimated weight 0. 30 carats). Above the emerald is a small round diamond measuring 1. 4 mm, adding a subtle accent of brilliance. The pendant features a hallmarked bale and is suspended from an 18 carat gold neck chain measuring 18 inches in length. Total combined weight: 2. 1 grams.