There is something really special about coloured diamonds, and natural blue diamonds are among the rarest. Alexandre Reza designed for other high end jewellers before striking out on his own in Paris. These stunners have white pear shapes in the vicinity of 1 carat per stone on top, with pendant diamonds of about 5 carats beneath. Yes, please. The auction estimate is 600,000 – 1,200,000 Swiss francs.