4 Carat Cushion Sapphire Engagement Ring Art Deco4 carat cushion sapphire engagement ring Art Deco. This fantastic original Art Deco platinum ring features a stunning Ceylon blue sapphire. The 4. 48 carat cushion cut sapphire is delicately prong set, allowing maximum light and color to show. Surrounding the Ceylon blue sapphire are thirty two (32) single cut diamonds, which add additional sparkle from every angle. This fabulous Art Deco engagement ring is a true example of Art Deco craftsmanship and