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)
