LONDON, ENGLAND - FEBRUARY 04: A member of the Sotheby's auction house team holds the "Enigma" black diamond on February 04, 2022 in London, England. The 55-sided, 555-carat 'Enigma' black diamond, said to be worth $7million, will go on sale at Sotheby's on February 9th with cryptocurrency being accepted as payment. This carbonado diamond is mined close to the earth's surface suggesting possible extraterrestrial origins, either from meteoric impacts or from diamond-bearing asteroids colliding with the Earth. (Photo by Leon Neal/Getty Images)