Antique Art Nouveau 14K Rose Gold 2.5ct Amethyst Cabochon Ring. The ring is in great antique estate condition and ready to wear. The stone is a little loose and scratched. The ring is made of 14K rose gold and set with an approximately 2.5 carat cabochon cut amethyst. The ring is a size 6 and weighs a total of 3.4 grams. The ring dates from 1890 - 1900 and is an early example of the Art Nouveau style.