The rare Blue Moon Diamond during a preview at Sotheby’s, in Geneva, Switzerland, Wednesday, Nov. 4, 2015. The 12.03 carat blue diamond is the largest cushion shaped fancy vivid blue diamond ever appear at auction. It is estimated to sell between 35-55 million US dollars. The auction will take place in Geneva, on Nov. 11, 2015. (Martial Trezzini/Keystone via AP)