We don’t always get to pinpoint the exact moment the world changes.
But when the New Mexico dawn was torn open at 5:29 am on 16 July 1945, it was, without a doubt, a pivotal moment in humanity’s history.
That was the United States Army’s Trinity test: the detonation of a plutonium implosion device known as the Gadget – the world’s very first test of a nuclear bomb. And more than 80 years later, scientists are still finding the changes it wrought.
Now, in a mineral forged in the fury of the world’s first deliberate nuclear blast, scientists have found a crystal that, under more normal circumstances, wouldn’t be able to exist on Earth.
“Extreme, transient conditions produced by nuclear detonations can generate solid-state phases inaccessible to conventional synthesis,” writes a team led by geologist Luca Bindi of the University of Florence in Italy.
“We report the discovery of a previously unknown calcium copper silicate type-I clathrate formed during the 1945 Trinity nuclear test; the first crystallographically confirmed clathrate identified among nuclear-explosion products.”
The explosion itself was about as dramatic as could be expected for such a devastating moment.
The energy release was equivalent to 21 kilotons of TNT. It vaporized the 30-meter (98-foot) test tower and surrounding copper infrastructure, including cables and instruments used to record the blast.
The resulting fireball fused the tower and copper with the asphalt and desert sand that was drawn up into the mushroom cloud, turning the mixture into a glassy, never-before-seen material later named trinitite.
It’s within this material that scientists have found some strange structures. In 2021, Bindi and his colleagues identified an unexpected quasicrystal in the rare red form of trinitite that contains metal from the tower, cables, and recording instruments… and now this variant of the material has yielded another surprise.
Right next to the quasicrystal, the researchers found a clathrate – a crystal structure that consists of atoms arranged in a cage-like lattice that can trap other atoms inside.
Crystal is a term used to describe the arrangement of atoms inside certain materials, and most crystals form under stable conditions. Inorganic clathrates are special because they require very specific conditions to form, and they are rarely found in nature.
Some such conditions were briefly met during the Trinity explosion: extreme shock, temperature exceeding 1,500 degrees Celsius (around 2,730 degrees Fahrenheit), and pressures of 5 to 8 gigapascals, which then dropped off rapidly.
This rapid change, followed by rapid cooling, allowed atoms in the trinitite to assemble into unusual configurations, then become locked in place, creating structures that otherwise would not be able to form.
This material is basically a moment frozen in time, preserving a mineralogical snapshot of the brief temperature and pressure conditions generated during the detonation – a treasure trove for scientists.
Investigations of red trinitite have already revealed a range of unusual phases – and the clathrate emerged during one such analysis.
Using X-ray diffraction, the researchers probed a sample of red trinitite and identified a copper-rich droplet embedded therein.
Further investigation revealed an unusual atomic configuration – a cubic type-1 clathrate, in which ‘cages’ of silicon atoms hold single calcium atoms, with traces of copper and iron present.
It represents the first clathrate ever found in the products of a nuclear explosion.
Here’s where it gets odd, though. Since the same conditions that form clathrates also promote the formation of quasicrystals, and the clathrate and the quasicrystal had similar compositions, Bindi and his colleagues thought the two structures might be related.
They performed mathematical modeling to determine whether the quasicrystal could have emerged from the clathrate, but the results strongly suggested that, while this pathway is possible in general, in this particular instance, the copper concentration was too high.
This means that two very different crystal phases, formed from the same materials under the same extreme conditions, arose independently within the same sample.
Related: Physicists Create New Type of Time Quasicrystal – Inside a Diamond
“These findings rule out a simple clathrate-based structural interpretation for the Trinity quasicrystal and emphasize the distinct nature of silicon-rich phases generated under extreme conditions,” the researchers write.
Research like this can help scientists better understand the effects of nuclear testing and even offer new forensic tools for investigating sites where such explosions have occurred.
More broadly, the researchers note, “this work underscores how rare, high-energy events – such as nuclear detonations, lightning strikes, and hypervelocity impacts – serve as natural laboratories for producing unexpected crystalline matter and for critically testing and constraining structural models beyond the reach of conventional synthesis.”
The findings have been published in the Proceedings of the National Academy of Sciences.
