18ct white gold 045ct diamond 474ct tanzanite oval drop necklace132383 1 this sublime necklace features a huge 474 carat oval tanzanite which showcases the beautiful lavender blue colour for which this highly prized gemstone is famous held by four claws in an 18 carat white gold setting this rare gemstone is suspended by a curve of brilliant cut pave set diamonds this curve provides a clever hidden bail meaning that there is no interruption to this sleek and contemporary design the 18ct