18ct white gold whitby jet 290ct diamond multi stone necklace n786 this sublime necklace features a total of 22 cabochon pieces of whitby jet that drape around the neck in a contemporary bubble design set in 18 carat white gold these exceptionally rare gemstones from the north yorkshire coastline are surrounded by 290 carats of brilliant cut diamonds as the necklace crests the shoulder these diamonds are replaced with smooth 18 carat white gold circles allowing for the utmost comfort whil