18ct white gold tanzanite and diamond princess cut necklace the tanzanite collection by tivon showcases one of the worlds most desired stones that is considered a thousand times rarer than the diamond this seductive gemstone can exhibit a variety of surreal colours including blues violets and burgundies so each piece is truly unique and beautiful this simple but stunning necklace is a gorgeous piece that boasts a 104ct tanzanite stone that contrasts beautifully to the white gold it is set