Sotheby's auction house announced today, Monday, that a rare and exceptionally pure diamond, expected to fetch up to $15 million, will be available for purchase at an auction next month using cryptocurrencies. Sotheby's stated that this will be the first time a diamond of such size is offered for public purchase with cryptocurrency. The diamond, weighing 101.38 carats, is one of only eleven diamonds weighing over 100 carats ever offered for sale at auction. Pre-sale estimates for the diamond's price range from $10 million to $15 million, and it will be sold on July 9 in Hong Kong. Both Bitcoin and Ethereum will be accepted, along with traditional currencies for payment.