925 Silver Ring 5mm Band with Onyx 2cm x 1.5cm VG 5.5 Marked

This 925 silver ring is used but in very good condition. There is light tarnishing/scuffing/scratching from use. It is marked 925. There is what looks like a maker's mark but I can't make it out. The band width is 5mm. The main portion measures approximately 2cm x 1.5cm.