Mexican Sterling Silver & Black Onyx 3pc Set.Â A very lovely pin and earring set designed with an Aztec mask carved out of black onyx on the pin as well as the earrings. The earrings are screw-back style of long ago but could easily be converted to today’s pierced style. The pin measures 1 7/8″ high x 2 1/8″ wide; earrings are 7/8″ high x Â¾” wide. All three pieces of the set are marked: Silver â€“ Mexico. The clasp is a “Hold-On” gold tone clasp with Pat. No. 13009, it is in perfect working condition.