A rare 555.55-carat black diamond, named “The Enigma,” has been listed for auction by Sotheby’s and is expected to sell for over $6 million.
![](https://www.gannett-cdn.com/presto/2022/01/19/USAT/46e109d5-821c-48f4-bd4c-db8e8e8ee70b-black_diamond.jpg)
Rare 555.55-carat black diamond, thought to be forged in space, to be sold at online auction
Jan 19, 2022 | 1:48 PM