This is a small marquis cut opal in an illusion setting with stylized swirl detail on the band. This ring is a size 7. VERY pretty ring, and lots of detail.The size stones tested as diamonds and were tested on a Presidium Gem Tester. However it cannot tell synthetic from natural and these are probably cz's. The moonstone was looked at by a jeweler. The ring is marked 10K. Contact me with any questions!