The oval cut black onyx measures 10 x 12mm.
- Lifetime Guarantee - 60 Day Worry-Free Return - Oval Black Onyx & Diamond Men's Ring Crafted in Solid White Gold, by SuperJeweler Available in ring sizes 8-12. Oval Black Onyx & Diamond Men's Ring Crafted in Solid White Gold, by SuperJeweler.5.12 carats, diamond color is I-J, diamond clarity is I2.