I read this as CO-Star, but maybe your initials are CO. This is a 10k yellow gold "CO-Star" signet ring with star set diamond. Size 9.5. Face - 9x15mm. Diamond - 2.4mm. 6.39g. Stamped "10k" and an illegible makers mark.
This was a college sport's ring. There were very deeply engraved logos on each side of the ring that my jeweler did an amazing job of filling and polishing out.
