1 Carat Marquis Cut Diamond & Sapphire Halo Ring in Platinum1 Carat Marquis Cut Diamond Sapphire Halo Ring in Platinum. This stunning modern engagement ring features a 1. 01 carat marquise cut diamond at its center. The center diamond is bezel set, allowing the top of the stone to be in full view. Sixteen (16) french cut sapphires and twelve (12) round brilliant cut diamonds accent the center diamond. The sapphires provide an incredible contrast of color and texture, allowing the center stone to shine.