You are viewing an 18K yellow gold custom Black Onyx and Diamond ring made in the 1980's. In the center is a custom cut piece of Black Onyx. On either side of the Black Onyx are a row of nice quality accent Diamonds weighing around 1/4 of a carat in total. The ring is marked 18K. It measures 9 mm long up the finger by19 mm or 3/4" across ; and, it stands up off the finger 8 mm.The ring is between 7 to 7 1/4 size; and, it could be re-sized. The ring weighs 15.5 grams.