Blue perfection. B. Brilliant's pretty circular stud earrings feature round-cut London blue cubic zirconias encircled by round-cut clear zirconias (3 ct. t.w.) set in sterling silver. Approximate diameter: 3/8 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.