555Jewelry Solid Stainless Steel Signet Ring, Black Onyx Plain Signet Seal Ring for Men, Vintage Rings for Men, Pinky Rings for Men, Biker Ring for Men, Gold, Size 7|Amazon.com
Black Onyx Square Signet Ring | Mejuri
Black Onyx Stone Ring, Onyx Signet Ring, Sterling Silver Signet Ring, Mens Black Onyx Ring, Mens Stone Ring - Etsy
Men's Vintage 14K YG Black Onyx Signet Ring, Size 10, Circa 1950 - Colonial Trading Company