A 100-carat perfect diamond that will be auctioned in April is shown at Sotheby's auction house in London. Carl Court/Getty Images The stone during the cutting and polishing process. Courtesy of Sotheby's The original rough stone weighed over 200 carats before it was cut and polished to its current state. Courtesy of Sotheby's The 100-carat diamond will go on a worldwide tour before going up for auction in New York. Courtesy of Sotheby's Viewed over purple, the diamond is expected to fetch $19 million to $25 million. Courtesy of Sotheby's Prev Next
