At a Glance
- A man’s brain was discovered preserved in glass after dying in the 79 AD eruption of Mount Vesuvius, marking the only known instance of human tissue vitrified by a volcanic event.
- His remains were found in Herculaneum, where an intense ash cloud exceeding 510°C struck before the pyroclastic flow, instantly heating the body and initiating the rare preservation process.
- Scientists found black glass fragments in his skull containing detailed neuron structures, revealed through electron microscopy. This highlights a preservation phenomenon never before observed in humans or animals.
- The transformation occurred due to rapid heating followed by sudden cooling, allowing molten brain matter to vitrify. This challenges assumptions that pyroclastic flows alone caused fatalities in ancient eruptions.
- The study underscores how dangerous fast-moving volcanic ash clouds can be and suggests enhancing building resilience to protect communities near volcanoes from extreme heat events during eruptions.
A new study has revealed an extraordinary discovery: the brain of a man who died during the eruption of Mount Vesuvius in 79 AD has been preserved in glass. This rare occurrence is the only known case of human tissue turning into glass due to a volcanic event. The man’s remains were found in the ancient Roman city of Herculaneum, which was buried under a blanket of hot ash and pyroclastic flow. The scientists who studied the man’s brain believe it was exposed to a blast of heat that reached temperatures above 510°C (950°F), much hotter than the pyroclastic flow.
Mount Vesuvius erupted catastrophically, sending clouds of ash and gas into the atmosphere. These clouds can be extremely hot and deadly, often causing rapid death. However, the new study suggests that the man’s brain turned to glass after exposure to a fast-moving ash cloud that was even hotter than the lava flow. The scientists discovered that the man’s brain, preserved in black glass fragments, showed detailed structures of neurons and other brain cells, which they examined under an electron microscope. This preservation method is unlike anything seen before in human or animal tissues.
The study, published in Scientific Reports, shows that the brain’s transformation into glass resulted from rapid cooling after exposure to high temperatures. Scientists determined that the brain was subjected to a quick and intense blast of heat, which then cooled down rapidly, allowing the transformation to glass. This unique process provided an unprecedented glimpse into the effects of volcanic eruptions on human tissue. The study also challenged previous assumptions, suggesting that it was not the pyroclastic flow alone that killed the people of Herculaneum but rather the ash cloud that preceded it.
The discovery of the glass brain provides a critical lesson about the dangers of volcanic ash clouds. These hot blasts, which can be poorly studied due to their fleeting nature, pose a significant threat during volcanic eruptions. Scientists hope that by raising awareness of this danger, future measures can be taken to protect people living near volcanoes. This includes making buildings more resistant to extreme heat, potentially saving lives in future volcanic disasters.
References
- Lawler, D. (2025, February 27). How did this man’s brain turn to glass? Scientists have a theory. Phys.Org; Phys.org. https://phys.org/news/2025-02-brain-glass-scientists-theory.html
- Giordano, G., Pensa, A., Vona, A., Di Genova, D., Al-Mukadam, R., Romano, C., Deubener, J., Frontoni, A., & Petrone, P. (2025). Unique formation of organic glass from a human brain in the Vesuvius eruption of 79 CE. Scientific Reports, 15(1), 5955. https://doi.org/10.1038/s41598-025-88894-5
