Edwardian 10K Yellow Gold Black Onyx Signet Ring Estate Jewelry. US Ladies Size 7. Marked 10K. This ring could be worn by a man or a woman. We believe this ring 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. Last photograph shows two solid gold black onyx rings in stock in our shop. This 10K estate ring is in very good condition.