18k white gold sapphire and diamond necklace18k white gold sapphire and diamond necklaces ring, 1. 12 ct total diamond weight and 2. 5 cs total sapphire weight. The sapphire portion of the pendant is articulated and allows it to be turned to the outside edge of the piece and can be worn as a gorgeous ring when the chain necklace is removed. The weight of the necklace is 12. 5 grams. The necklace measure29 mm.