black stone with ivory carving - cameos

by carol
(owensboro)

I have an old cameo that I took to an antique dealer who could not give me an appraisal, because he had never seen one like it. It is a black stone with ivory carving, but it is place in a solid pounded silver set with filigree surrounding it. Is it authentic being set in a solid back? How do I find someone that can give me a accurate appraisal