Belle Epoque enamel and diamond ring! The enamel design reminds me of locust wings... the composition of this ring is beyond beautiful.
(For those unfamiliar with Belle Epoque jewelry, it is the same era as Edwardian. If you would like to learn more about these terms and eras of jewelry, Lang Antiques has their Antique Jewelry University. And if you want a quick crash course, Ebay also has a wonderful tutorial for buying antique and vintage jewelry.)