Kobelli 2.7ct Radiant Moissanite and 2/5ct Diamond Drop Halo Comfort Fit Engagement Ring in 14k Gold A large 2.7 carat (9x7mm) radiant-cut moissanite is carried to the top of this diamond-lined engagement ring. Pairing the lab-created center stone with the earth-mined side stones makes for ideal use of both these stone types. The moissanite is best displayed in large sizes to showcase its well-known trait of brilliance and fire. The diamonds line together for a glittering visual enhancing the ri