If you are passionate about beautiful objects, mineralogy and space and you have a few million available, Sotheby’s has a real treasure to offer you.
During auctions spotted by SciencePost, the famous house Sotheby’s will soon sell a exceptionally rare lot, since it would have literally come from another world: the Enigma, a gigantic black diamond of 555.55 carats (the “largest cut diamond in the world” according to Guinness) apparently originating in the depths of space.
This fabulous mineral is part of a subgroup of diamonds called “carbonado“. Its representatives are special in many ways, starting with their unusual color which can range from brown to deep black through a whole palette of gray. Moreover, unlike classic diamonds, they are not entirely transparent. Even when polished, they remain relatively opaque due to their very particular molecular structure.
Indeed, in a standard diamond, carbon atoms are carefully aligned; they fit into an extremely regular cubic pattern which gives them their exceptional hardness. Carbonados, on the other hand, are polycrystalline aggregates; very summarily, this means that they are made up of a set of tiny diamonds whose crystal lattices are not aligned with each other.
A treasure from the cosmos?
But the most interesting point is certainly the question of the origin of these carbonados. For classic diamonds, this process is well known; they result from the compaction of carbon atoms under absolutely infernal pressure and temperature conditions, in the bowels of our planet. They then emerge thanks to the different geological cycles before being extracted, transformed, crimped, then sold at astronomical prices.
In contrast, the seemingly inconsistent distribution of carbonados on Earth seems at first glance inconsistent with this explanation. Research has therefore focused on other possible origins; very quickly, all eyes turned to the cosmos. Since the mid-2000s, several studies have concluded that these diamonds were formed in extremely hydrogen-rich environments unlike any found on Earth…but found in abundance in interstellar space.
In all likelihood, these carbonados may have been produced during a supernova explosion before arriving on Earth via a meteorite. They could also have been formed during the impact of a titanic meteorite, heavy enough to generate dantesque pressure and temperature conditions. Despite fairly evocative clues, it should be remembered that there is still no absolute scientific consensus on this question. Their spatial origin is therefore to be taken with a grain of salt.
If you have a few million to spend, this stunning piece will be auctioned from February 3-9; the auction firm is confident of raising at least 6 million euros.