Retro Round Brilliant & Single Cut Diamond Engagement RingRetro Round Brilliant Single Cut Diamond Engagement Ring. This Retro engagement ring features . 10 carats of diamonds set in 14 karat white and yellow gold. The primary stone is a . 08 carat round brilliant that is set in a square mounting with fishtail prongs to really bring a burst of life into the design. Below, the shoulders are also set in white gold and hold single cut accent diamonds with little scooped out spaces to let enough light in for