An 18k white gold diamond and onyx ring by Cartier. The unique ring is made up of a cushion shaped onyx, complete with a diamond set, open work, geometric pattern around the outer edge. The motif measures 22mm X 20mm. The ring is currently a size L but can be adjusted for a perfect fit and has a gross weight of 18.73 grams. The ring comes complete with a RichDiamonds presentation box and our own certificate of authenticity.