The atomic bombing of Hiroshima created a completely new material never before seen on Earth, scientists have discovered.
Researchers analysing tiny grains hidden within fallout debris have identified a previously unknown metal alloy that appears to have formed inside the nuclear fireball itself.
The microscopic alloy was found inside a glassy particle known as a ‘hiroshimaite’ that was recovered from beach sands in Hiroshima Bay.
The team say it was forged from a cloud of metals created when temperatures exceeding 7,000°C vaporised buildings, soil, glass and other materials.
The newly identified alloy contains iron, chromium, nickel, manganese, molybdenum, silicon and aluminium in proportions resembling stainless steel, but arranged in a structure never previously documented.
Researchers believe the molten vapour rapidly condensed before the fireball’s intense cooling froze the atoms into place.
However, the atoms are locked into a pattern that shouldn’t naturally occur in a metal with this mix of ingredients.
This makes it a completely unexpected find – and suggests other undiscovered particles could still be hidden in Hiroshima’s fallout debris.
Researchers have identified a previously unknown metal alloy that appears to have formed inside the nuclear fireball itself
The newly identified alloy contains iron, chromium, nickel, manganese, molybdenum, silicon and aluminium in proportions resembling stainless steel, but arranged in a structure never previously documented
For the study, the team, from the University of Florence, analysed 34 tiny glassy particles they had collected from beaches in Hiroshima Bay.
Using high–powered electron microscopes, chemical analysis and single–crystal X–ray diffraction, they searched the microscopic debris for unusual materials created during the 1945 atomic bomb blast.
One metallic grain measuring just a few micrometres across stood out because its chemical composition and crystal structure did not match any previously known alloy.
The team then compared its atomic arrangement with thousands of known materials to confirm it represented a previously undiscovered metal that formed inside the nuclear fireball.
‘We report the discovery of a previously unknown multicomponent alloy… recovered from beach sands of Hiroshima Bay, formed during the 6 August 1945 atomic airburst,’ they wrote in the journal Science Advances.
‘The alloy likely formed by condensation from a mixed metallic vapor followed by ultrafast quenching in the expanding fireball.’
The team said the alloy appears to occupy a previously unknown ‘sweet spot’ in materials science, created by the intense heat and rapid cooling inside the nuclear fireball.
The finding follows the discovery of rare quasicrystals in debris from the first–ever atomic bomb test in New Mexico, adding to evidence that nuclear explosions can forge exotic materials impossible to recreate.
The microscopic alloy was found inside a glassy particle known as a ‘hiroshimaite’ (pictured) that was recovered from beach sands in Hiroshima Bay
The atomic bomb dropped on Hiroshima was codenamed ‘Little Boy’ and was the first nuclear weapon ever used in warfare
Understanding how the alloy formed could help scientists create similar structures in the laboratory, potentially leading to stronger, lighter or more heat–resistant materials.
‘This study demonstrates that anthropogenic (man–made) extreme conditions can lead to the formation of previously unknown materials,’ they concluded.
The atomic bomb dropped on Hiroshima was codenamed ‘Little Boy’ and was the first nuclear weapon ever used in warfare.
It was dropped on August 6, 1945 at 8.15am local time during the final weeks of the Second World War.
The bomb exploded approximately 1,900ft (580m) above Hiroshima to maximise the area of destruction, releasing energy equivalent to around 15,000 tons of TNT.
Between 60,000–80,000 people are thought to have died immediately. By the end of the year, the death toll had risen to around 140,000 due to burns, injuries and radiation sickness.
Tens of thousands more people later died from cancers and other radiation–related illnesses.
A separate study, published earlier this year, found that the world’s first nuclear explosion over New Mexico forged an ‘impossible crystal’.
The team says the alloy was forged from a cloud of metals created when temperatures exceeding 7,000°C vaporised buildings, soil, glass and other materials. Pictured: The devastation after the atomic bomb attack
During the Trinity test, engineers from the Manhattan Project detonated a plutonium implosion device known simply as ‘The Gadget’.
The energy released was equivalent to 21,000 tons of TNT, and instantly disintegrated the 98 – foot (30m) test tower and copper infrastructure.
The nuclear fireball swept up and fused the tower, measuring instruments, and desert sand, raining down molten blobs of an entirely new mineral known as Trinitite.
Once prized as a morbid souvenir, scientists have now found that this strange mineral contains crystal structures that should have never been able to form on Earth.



