Blue Diamond (1 Carat)

Not only are they rare, but they are also known to have a spectacular shine. Of all the other gemstones, they are arguably the most popular among people. The Oppenheimer Blue Diamond is the largest vivid blue diamond ever to be auctioned. It was sold for 57.5 million dollars for a weight of 14.62 carats, or 3.39 million euros per carat.