The listing, Vintage Intaglio Gold -Tone Reverse Cameo has ended.
intaglio, which is sort of a reverse cameo -- instead of being on top of the glass or stone, it's cut into the back side. Has dogtooth prongs.
It is small less than inch. Chain is nothing special. 8 inches.
What's kind of cool is you can change the color by changing the cloth. To any color you may want. or leave it clear.
I searched the internet couldn't find another one like it.
So not sure on the age my guess 1930's or 1940's Its not signed .