Edwardian 10K Yellow Gold Black Onyx Signet Ring Estate Jewelry. US Size 7. Marked 10K. This ring could be worn by a man or a woman. We believe this is a signet ring and could be engraved with an initial or other symbol. This ring is can be resized by your local jeweler. Really fine black onyx is becoming difficult to find. We will ship this old beauty in a ring box. This antique 10K estate ring is in very good condition.