Three Stone Marquise Diamond Engagement Ring in 14KThree Stone Marquise Diamond Engagement Ring in 14K. This modern engagement ring features a . 95 carat marquise cut diamond set in 14 karat yellow gold. The marquise cut has recently seen a surge in popularity, and this one is GIA certified. A rather shallow cut, marquise diamonds often appear larger than comparable weights of more traditional cuts. This stone is set on both sides by round brilliant cut diamonds to complete this beautiful look.