The world’s largest cut diamond went under hammer at the UK’s famous auction house Sotheby’s on Thursday.

The extremely rare diamond, named “The Enigma”, was exhibited to the public in Dubai, Los Angeles and London before the auction.

“Today we are extremely excited to present The Enigma, a truly rare fancy black carbonado diamond weighing a staggering 555.55 carats with precisely 55 facets, a technical feat for one of the toughest diamonds in existence,” said Nikita Binani, Sotheby’s jewelry specialist.

Speaking to Anadolu Agency, Binani said the “Sotheby’s “will be offering this absolutely unique object of art and something that is much more than a jewel, with no reserve for purchase at cryptocurrency.

“We are very excited to mention that this diamond has been recorded … as one of the largest fancy black diamonds and also the largest cut diamonds ever to be recorded and known in the world,” she added.

The Enigma was listed as the world’s largest cut diamond by the Guinness Book of World Records in 2006.

Unlike most diamonds formed deep within Earth, carbonados are found in alluvial, sedimentary deposits, close to or on Earth’s surface, the auction house explained.

“This, and their specific mineral make up suggest possible extra-terrestrial origins, either from meteoric impacts producing natural chemical vapor deposition or from diamond-bearing asteroids colliding with the Earth.”

The diamond “surpasses the weight of both the Great Star of Africa, 530.2 carats, and the Golden Jubilee, 545.67 carats, making it not only one of the largest fancy black natural-color diamonds in the world, but also the largest faceted diamond to ever appear on the auction market.”

Black diamonds are thought to have been formed from a meteoric impact or diamond-bearing asteroid that collided with Earth approximately 3.8 billion years ago, and believed to be a rare natural occurrence only found in Brazil and the Central Republic of Africa.

The diamond will receive online bids between Feb. 3 and 9./aa