2.81 Cushion Sapphire Engagement Ring 18kThis solitaire engagement ring features a GIA certified 2. 81 carat cushion cut purple sapphire in two tone 18 karat rose and white gold. The unheated purple sapphire shows rich color saturation and the cushion cut creates soft, rounded corners with brilliant faceting. Set in a four prong white gold basket, the center stone sits on a knife edge rose gold band that tapers gently toward the gemstone. The GIA certificate (6224335376) confirms this