Emerald with Diamond Pendant Set in 18 Karat Gold Settings For Sale at An 18 carat gold Emerald and Diamond Pendant 18K Diamond and Emerald Necklace For Sale 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.