Rose Cut Diamond Cocktail Ring in 18k White GoldRose Cut Diamond Cocktail Ring in 18k White Gold. This modern cocktail ring features 13. 62 carats of rose cut diamonds set in 18 karat white gold. The diamonds have quite a lot of variety in shapes and color, but sitting together tightly in their bead setting they give the ring a massive presence. This is the type of ring that will catch eyes and start conversations at a cocktail party.