These wonderful earrings are sterling silver with inlaid abalone which has flashing shades of greens, pinks and blues. They measure 1 1/4" x 1" and are screw-on style. The mark is quite worn in places, but it reads "Hecho en Mexico 925" and what I believe is "RPB" (though it might be RRB). There is also a mark on the screw cartouche but it is too faint to read. Beautiful sterling earrings!