With a final bid that closed the sale at $4.28 million, an anonymous person became the new owner of a 555.55-carat black diamond named The Enigma.
The sale of this bizarre stone caused a debate about its origin as everyone was intrigued by the controversy that it may have actually arrived from outer space.
The Formation of Carbonado Diamonds
The Enigma and other carbonado diamonds formed in a mysterious event some 3.8 to 2.6 billion years ago. Carbonados have a distinctive jet black color.
They’re opaque and have plenty of holes. They’re said to be a one-of-a-kind combo of chemical and physical properties that are not seen in any other diamonds.
This diamond is found in only two parts of the world, that is, in the Central African Republic and Brazil. They can grow very large. The largest-ever diamond and largest carbonado found was the 3167-carat Brazilian one known as Sergio.
The Enigma is not small either. It’s actually almost the size of a racquetball. Until recently though, carbonados weren’t recognized for their beauty, but rather for their strength.
Unlike traditional gem diamonds with single crystals, carbonados consist of an interlocking crystal network and this adds resistance to cracking under pressure.
They’re valuable as industrial abrasives and have been used as drill bits because of their ability to penetrate rocks as well as with grinding wheels for tool sharpening.
The Mysterious Origin of the Carbonados
The numerous oddities surrounding the carbonados have triggered plenty of theories about their origin.
And, there’s no model that gives an explanation for everything, according to Wuyi Wang the VP of research and development at the Gemological Institute of America who certified The Enigma as a carbonado.
Black diamonds were found in the 1840s by eastern Brazil miners who gave them the name carbonado after the Portuguese word for carbonized or burnt.
Decades after, they also appeared in the Central African Republic. The carbonados from these two locations are very similar so they’re probably related, according to experts.
Peter Heaney, a mineralogist from Pennsylvania State University explains that carbonados probably deposited during the joining of two landmasses as a single swath some billion years and they split into these two locations after the last supercontinent Pangea broke apart 180 million years ago.
Each of the carbonados tells a different story and there’s no host rock, so scientists look for clues in the unusual properties of the black diamonds.
The Enigma’s origin is unknown and it’s estimated to be more than 800 carats, weighs 160 grams, and it was later cut into a 55-facet shape. This task required three years due to the extreme strength of the diamond.
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