MOP Cameo Ring Marcasite Sterling Silver Size 7 Onyx 925 OOAK BeadRage

This is a beautiful piece - mint condition - never worn - size 7 - not adjustable - could be but not by me (no equipment) pave set genuine marcasite surrounds a lovely mother of pearl cameo that is mounted on an onyx cabochon. This one has a very thick plain band underside. Nice victorian look. Stamped 925 inside with some kind of additional stamp I can't make out. Only piece I have - NBW.