The Wittelsbach Diamond started as a fancy deep grayish blue diamond weighing in at 35.56 carats. Origins unknown, the diamond "appeared" in 1962 and was determined to be of Indian origin. Passing from one royal family to another, it was eventually sold at auction in 2008 for $23.4 million to London-based jeweler Laurence Graff. Graff then recut the stone, revising it to a Internal Flawless 31.06 carats Fancy Deep Blue Diamond. The biggest blue diamond in the world.