via Associated Press An employee of Sotheby's Dubai presents a 555.55 Carat Black Diamond "The Enigma" to be auctioned at Sotheby's Dubai gallery, in Dubai, United Arab Emirates, Monday, Jan. 17, 2022. DUBAI, United Arab Emirates — Auction house Sotheby’s Dubai has unveiled a diamond that’s literally from out of this world. Sotheby’s calls the 555.55-carat black diamond — believed …