Here is a simple gold fede gimmel ring. This particular one does not open up, it possible did at some point but has been soldered permanently closed.

Width: 5 to 1.9 mm wide
Metal: 14k yellow gold
Markings: none
Finger Size: 5 (can be sized)
Circa: 1900
Weight: 1.4 grams
Condition Rating: 6 (does not open, possibly soldered shut, has been cleaned but not polished)

Thanks for looking!