Mexican sterling pin with bezel set black onyx center stone and ruffled edge. Stamped on the back Mexico 925 C11. Measures 2 1/8" X 1 5/8". Clasp works well and is secure. Weight is 16.48 grams. Tiny bit of green oxidation. I always leave the cleaning to the buyer as some like it as original as possible. Featured in the book Mexican Silver Jewelry Details by Leslie Pina.