EFENew York

An extremely rare black diamond weighing 555.5 carats will go under the hammer in February, Sotheby's announced Monday.

With its 55-facet cut, the diamond, dubbed the Enigma, will become the largest of its kind to be put up for auction, according to the world-renowned British auction house.

Sotheby’s said the diamond, which was listed in the 2006 Guinness Book of World Records, will be sold to the highest bidder, expecting it to fetch between 3 to 5 million pounds sterling ($4.1 million – $6.8 million).

Nikita Binani, Sotheby’s head of sales, told Efe that the Enigma is a rare piece that cannot be easily compared to other diamonds, or even other black gemstones that went on the market in the past.