Hi there. I have a silver ring with a mottled stone (no idea what stone it is), with a mystery set of marks on the outside of the band. The first stamp seems to be a hexagon with '5 ?8 2 B' in it, the second a mark that looks like a P or a snake's head or a drooping flower bud in an oval stamp, and underneath this something not easy to make out but which could be a head or face in profile. Any help with identification will be most gratefully received. Thanks!

