18ct white gold whitby jet 654ct diamond marquise necklace n788 this sublime necklace features a total of 59 marquise cut pieces of whitby jet that drape continuously around the neck in a contemporary lariat design set in 18 carat white gold these exceptionally rare gemstones from the north yorkshire coastline are surrounded by brilliant cut pave set diamonds as the necklace crests the shoulder these diamonds are replaced with smooth 18 carat white gold surrounding the whitby jet allowing