A rare 555.55-carat black diamond, dubbed “The Enigma,” will be up for auction in February. Auction house Sotheby’s expects the diamond to be sold for at least $6.8 million.

“The shape of the diamond is based on the Middle-Eastern palm symbol of the Khamsa, which stands for strength and it stands for protection,” jewelry specialist at Sotheby’s Dubai Sophie Stevens told The Associated Press. Khamsa means five in Arabic.

Stevens also said the black diamond is likely from outer space.

“With the carbonado diamonds, we believe that they were formed through extraterrestrial origins, with meteorites colliding with the Earth and either forming chemical vapor disposition or indeed coming from the meteorites themselves,” she said.

The rare gem was shown off on Monday to journalists as part of a tour in Dubai and Los Angeles before it is due to be auctioned off in London. The auction house plans to accept cryptocurrency as a possible payment as well.