A beautiful and fairly substantial piece. Measures a bit better that 1 3/4 inches. It's a very thick pin and deeply carved and polished. I cannot tell you what it is made of. Certainly looks as though it's jet, or gutta percha but, I'm just not sure. It has a primitive tube hinge and c clasp. A view of the back has been provided. The workmanship is excellent. It is a beautiful pin no chips or damage noted. 1860's, possibly earlier.