The record-breaking 555.55-carat black diamond, dubbed the Enigma, is up for sale at Sotheby’s. The online sale of the stone will take place on February 3-9 in Dubai, Report informs.

The owner of the diamond, who has not been named, purchased it in rough form in 1999 or 2000. Then the weight of the stone was more than 800 carats, and its processing took several years, as a result of which it has 55 facets. Sotheby’s adds that this is the largest fancy natural black diamond in the world. In 2006, it entered the Guinness Book of Records as the largest cut diamond in the world.