Large Art Nouveau Gold Moonstone Ring - I would like to find its maker/origin.

I found this unusual ring a few years ago in the costume jewelry showcase at a charity thriftstore for $4.98. I'm sure the workers in the store thought it must be costume because it is so large and somewhat gaudy. In addition, it has a small crack in the shank portion of the ring due to wear that makes it appear to be adjustable in size. It is small in size--approximately a size 4. As you can see in the picture, it makes a huge pinky ring on my hand. I have been unable to find a makers mark or any other markings on this ring. I have searched the internet and determined that the stones are moonstones. They change color from almost clear to blue/green and purple depending on the movement of the light. I am posting this due to the similarities between it and another piece of jewelry posted on this page (a necklace) that has similar cut-out designs in the gold on the back and one large stone that appears to be a moonstone as well. I am hoping that someone will recognize the origin or maker of this jewelry. It appears to be a very finely crafted piece with a lot of detailed hammered designs on the dome around the stones. From underneath, it appears to have been hand hammered into shape and then the back of the dome was smoothed out. Someone commented on this site that the similar necklace could be of Asian origin. I believe that could be the origin of this ring as well. Any information that anyone can provide would be greatly appreciated.
Thanks......!