Perfectly poignant. Oval-cut onyx (2-3/4 ct. t.w.) sits in a bed of sterling silver and sparkling, single-cut diamonds (1/6 ct. t.w.) for a bold, yet elegant, statement. Approximate diameter: 1/2 inch. 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.