Engagement Ring Modern .69 Oval Cut Sapphire in 18k White Gold. This Modern sapphire and diamond engagement ring is finished in brightly polished 18k white gold. Bezel set into the center is a .69 carat oval cut blue sapphire. The sapphire has rich blue tone with accents of crimson and lavender purple when tipped into the light. To each side of the center sapphire are a row of shared bead set Round Brilliant cut diamonds. These diamonds cascade down the shoulder of the ring and form a solid 18k white gold shank.