Trustmark 14k Yellow Gold 6mm Fiery White Created Opal Ball Stud Post Earrings, Lorraine Made with our gorgeous Fiery White created Opals! Style or Setting: Hallmarked Solid 14K Yellow Gold Cup post for Pierced Ears. Features our popular 6mm bead or ball size which measures about 1/4 of an inch. Professionally hand-set in our own US studios.