One Carat Round Cut Natural Blue Sapphire Necklace with halo diamonds necklace The depth and richness of the blue in this sapphire is reminiscent of velvet. Safely ensconced in a dazzling halo of pave diamonds (.50 carats-worth), this one-carat blue sapphire is absolutely dripping in elegance. This stunning necklace easily goes from the office to a romantic night in the town without missing a beat. In addition to ensuring a fabulous September birthday, this piece also doubles as a delightful 45th wedding anniversary gift!