Amethyst & Diamond Ring 18kt Two-tone Gold. We have for sale a very unique ladies amethyst and diamond ring set in freeform style mounting. The ring has two amethysts that are emerald cut (2.80cttw) and two round brilliant cut diamonds weighing (0.11cttw). It is hallmarked Kt 18 : #1091 and ring size 10. The amethyst is dark, strong, bluish-purple in color with the smaller one being chipped but intact in the setting. The ring was cast and handset, it is in very good condition. Included is an insurance appraisal of $2200.00.