In a remarkable scientific discovery, researchers have determined how the brain of a victim from the AD 79 eruption of Mount Vesuvius turned into glass.
Glass formation from organic materials is an extremely rare phenomenon, yet in 2020, a black, glassy substance was found inside the skull of an individual who perished in the catastrophic event.
The remains, uncovered in the ancient Roman town of Herculaneum—one of the cities buried by volcanic ash alongside Pompeii—belonged to a young man found lying face down on a bed. A new analysis of the glassy fragments discovered in his skull and spinal cord suggests that his body was exposed to temperatures exceeding 510 degrees Celsius (950 degrees Fahrenheit) before cooling rapidly in a process known as vitrification.
Guido Giordano, a volcanologist at Roma Tre University and lead author of the study published in Scientific Reports, explained:
“The process of transforming anything liquid into glass requires rapid cooling rather than just high heat.”
He compared the phenomenon to the formation of obsidian, a volcanic glass that emerges when lava cools quickly upon contact with water.
The prevailing theory suggests that a superheated ash cloud—not the slower-moving pyroclastic flows that buried the city—was responsible for the vitrification of the victim’s brain tissue. Unlike pyroclastic flows, which reach a maximum of 465 degrees Celsius (869 degrees Fahrenheit) and cool gradually, an ash cloud could have briefly raised temperatures to the necessary level for vitrification before dissipating rapidly.
The victim’s skull and spine likely shielded the brain from complete thermal breakdown, enabling fragments of the unique organic glass to form. Researchers further tested this hypothesis by systematically heating and cooling samples of the glass, confirming that a temperature of at least 510 degrees Celsius was necessary for the transformation.
However, some scientists remain skeptical. Forensic anthropologist Alexandra Morton-Hayward from the University of Oxford, who was not involved in the research, argued that organic tissues—primarily composed of water—typically require extremely low temperatures for vitrification, as seen in cryopreservation. She questioned whether the substance inside the skull was definitively brain tissue, suggesting alternative explanations should be explored.
Despite the ongoing debate, prior studies have identified neurons and proteins within the glassy fragments, reinforcing the theory that the material originated from the victim’s brain.
CNN, Independent, and Reuters cotributed to this report.
