This is a vintage pair of screw back earrings signed Silver Mexico. This is one of the oldest marks used on Mexican sterling jewelry. The earrings have a cabachon of Mexican jade or green onyx on them. The earrings measure 1-1/8 inches long. One earring is missing a portion of the screw which I tried to show in the pictures. I believe the earrings can still be worn. The earrings also have an age patina that I have not polished. Please let me know if you have any questions. Thanks for stopping by.