Old Spider Pin in 900 Silver Mexico

Old 1920s Mexican 900 silver spider pin. It has a lacy edged body and coiled legs. Very tarnished. It is marked 900.15,  but it tests sterling silver. (925) Measures 1 1/8" x 2 1/2". Weight: 8 grams. I did not polish this to preserve the patina, but it will polish to a high shine. Rare find.