1 Carat Marquise Diamond Engagement Ring in 14K Yellow Gold1 Carat Marquise Diamond Engagement Ring in 14K Yellow Gold. This marquise diamond engagement ring features a lovely 1. 03 carat genuine natural diamond. The primary diamond is nearly colorless with soft reflections of honey yellow. On both sides of the primary diamond lay two (2) . 05 carat accent diamonds. The 14k yellow gold band is elegant and traditional, leaving the focus to the beauty and brilliance of the marquise cut diamond.