Art Deco Sapphire & Diamond Cluster Ring in White GoldArt Deco Sapphire Diamond Cluster Ring in White Gold. Cluster rings offer such a romantic motif and with a . 40 carat cushion cut sapphire as the center stone, this art deco ring takes the romantic appeal even further. Set in 18k white gold and secured with ten (10) prongs, the lovely sapphire is surrounded by a halo of single cut diamonds. The thin shank is delicate in appearance and finished with a knife edge.