Image 1 of 2 Image 2 of 2 Sapphire diamond rectangular cluster ring $14,495.00 An 18 carat White gold, Sapphire and diamond cluster style ring. 2.47ct Royal blue Sapphire with 0.86ct RBC DEF Vs-si. Add To Cart Added! An 18 carat White gold, Sapphire and diamond cluster style ring. 2.47ct Royal blue Sapphire with 0.86ct RBC DEF Vs-si.