February 2022
The Enigma: 555-Carat Black Diamond Sells for $4.3 Million
The Enigma, a 555.55-carat carbonado black diamond believed to be of extraterrestrial origin, sold at Sotheby's London in February 2022 for £3.16 million (approximately US$4.3 million). The stone was purchased entirely in cryptocurrency, in one of the most high-profile digital-currency gemstone transactions to date.
Carbonado diamonds differ fundamentally from conventional diamonds in their polycrystalline structure and lack of the inclusions typical of Earth-formed stones. Scientists have proposed that the Enigma's origins may predate our solar system, potentially formed by a meteorite impact or in interstellar space. Its sale ignited debate within the traditional gem trade about the crossover between the crypto world and fine jewelry, with established auction houses increasingly open to alternative payment structures for headline lots.