Ornate elegance. Genevieve & Grace's sterling silver ring features a stylish pattern accented with marcasite and a yellow cubic zirconia (50 ct. t.w.) raises the bar on glamour. Size 7. Almost all gemstones and blue and black diamonds have been treated to enhance their beauty and require special care. All gemstone carat weights (ct. t.w.), if mentioned, are approximate; variance may be .05 carat. Ring Sizer.