Here is a very interesting Modernist pin. I was told that it is agate but it almost looks like a photograph. It is set into a 875 silver frame. According to the hallmarks I believe that it is Russian but it could also be Polish. It measures 1 1/4" X 1 X1/8. There is some silver polish residue in the corners. Other than that it is in perfect condition.
Vintage Russian Modernist 875 Silver Agate Sterling Pin