An extremely rare diamond believed to be from outer space will be going up for auction next month. Auction house Sotheby’s Dubai will be selling the 555.55-carat black diamond, known as "The Enigma," ...

Geologists still can't say for sure whether the enormous stone called the Enigma crystallized in Earth’s mantle or fell from outer space. Weighing in at 555.55 carats, or 111.11 grams, the carbonado ...

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 ...

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 to have come from outer space — "The Enigma." The ...

Last week, London auction house Sotheby’s unveiled the so-called “Enigma Diamond,” a 555.55-carat black diamond that will go up for sale next month. The plum-sized gem debuted at the Dubai Diamond ...