Embrace the finer things in life. Genevieve & Grace's square ring stuns with marcasite druzy (13-3/8 ct. t.w.) setting it apart. Ring set in sterling silver. 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. Custom ring sizing is not available for this item. Ring Sizer.