Help with a mark on an opal & gold ring

[MargaretBBaird]

The ring also has some damaged pearls set beside the two opals. Sorry about the blur on the image, but i hope it can be made out as what appears to be three ring shapes. This seems to be the only mark on the ring...
The furthest history i'm aware of on the ring is that it was gifted in approxiamately 1910 to a relative, by someone who dealt in such things (either antiques or jewlery). This occured most probably in Tennessee, United States.
Has anyone ever seen this mark (or type of mark) before? It's stumped me for some time and i'm grateful for any advice you can give.
-M

These are thumbnails, click for larger image.








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