The eruption of Vesuvius turned a man’s brain into glass - this is how it happened
28 February 2025, 07:42
Scientists have described how the heat from the eruption of Mount Vesuvius nearly 2,000 years ago was so intense it turned the brain of one of its victims to glass.
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The eruption in AD79 buried the Roman settlements of Herculaneum and Pompeii under metres of ash and pumice, killing thousands of people.
One of them, in Herculaneum, had his brain rendered into a dark form of glass in a process known as vitrification.
A study in the journal Scientific Reports has explained the phenomenon which has not been recorded at any other archaeological site.
Scientists believe that a thin but searingly hot ash cloud with temperatures above 510C swept through the town, killing people instantly
Brain matter would normally become a mix of glycerol and fatty acids under these conditions, however as the ash cloud dissipated, the man’s brain cooled rapidly enough to form glass.
The town was subsequently buried under hot pyroclastic flow deposits.
In order for the vitrification to occur temperatures must have reached in excess of 465C, according to Professor Guido Giordano of the Roma Tre University, who led the study.
"The glass formed as a result of this process allowed for an integral preservation of the biological brain material and its microstructures," he said.
"The only other type of organic glass we have evidence of is that produced in some rare cases of vitrification of wood, sporadic cases of which have been found at Herculaneum and Pompeii.
"However, in no other case in the world have vitrified organic human or animal remains ever been found."
Archaeologists believe the man was in his 20s.
He was found face down on a bed, and may have been asleep when he died. It is possible he was a guard at the nearby College of the Augustales, a building that may have been used as a meeting place for a cult dedicated to the emperor Augustus.
