Is the mysterious 'space diamond' for real? An investigation.

A profoundly curious gem is up for auction. The pear-shaped jewel called "the Enigma," cut with 55 gleaming sides, is dark and cryptic. The fine art company Sotheby's calls the unusual diamond "one of the rarest, billion year old wonders known to humankind." Bidding closes on Feb. 9, 2022. It may fetch millions. Most intriguing of all, unlike the diamonds commonly perched atop engagement rings, the Enigma might not have been forged in the deep geologic furnaces of our planet. As Sotheby's (fairl...