A glassy black rock found inside the charred skull of an unfortunate victim of the Mount Vesuvius eruption has turned out to be a 2,000-year-old vitrified human brain, reports Phys.org.

The remarkable finding is a testament to just how swift and devastating the eruption was. In A.D. 79, the town of Herculaneum was a popular seaside resort town for rich residents of Pompeii. Although seismic activity around the mountain had been increasing, such tremors were nothing new to those who lived in the shadow of Vesuvius. By the time residents were alerted to the eruption, it was already too late. Herculaneum was smoldered in a river of molten lava 50 feet deep.

One of many men caught in this disaster was the custodian of the College of the Augustales, center of the cult of Emperor Augustus. Archaeologists originally uncovered the man's charred remains back in the 1960s, laid out on his wooden bed. He had been preserved in ash, as if frozen in time. It wasn't until 2018, though, that a crevice in the man's skull opened up to reveal something glittering inside.

"In October 2018, I was able to look at these remnants and I saw that something was shimmery in the shattered skull," Pier Paolo Petrone, one of the researchers, told AFP.

It was a black rock, glassy like obsidian. It didn't take long for Petrone to understand what this hidden treasure was: super-heated, vitrified human brain.

In order to transform a human brain into glass, the heat where this man was sleeping would have had to have risen very quickly to about 970 degrees Fahrenheit. At that temperature, body fat ignites and soft tissues vaporize. After the intense burn, it would have had to cool very quickly to solidify the brain into a rocky form.

"The high heat was literally able to burn the victim's fat and body tissues, causing the brain to vitrify," the archaeological site of Herculaneum said in a statement.

Further analysis later confirmed that the rock contained bits of protein and fatty acids from a human brain. The discovery is being hailed as "sensational," and it might even be possible to extract this man's DNA from it.

"If we manage to reheat the material, liquefy it, we could maybe find this individual's DNA," Petrone told AFP. "That will be the next step."

Herculaneum wasn't the only town engulfed in lava and ash. The eruption of Vesuvius pulverized the Roman city of Pompeii, as well as Oplontis and Stabiae, along with many other smaller settlements along the way. It was one of the deadliest volcanic eruptions in European history, ultimately releasing 100,000 times the thermal energy of the Hiroshima-Nagasaki bombings. The remains of over 1,500 people have been found at Pompeii and Herculaneum alone, though the actual body count was likely far beyond what has been uncovered by archaeologists.

The findings from this latest discovery were published in the New England Journal of Medicine.

Bryan Nelson ( @@brynelson ) writes about everything from environmental problems here on Earth to big questions in space.

We know more about how the victims of Vesuvius died — and it's grim
The volcanic eruption of Vesuvius in A.D. 79 was so intense it turned one man's brain into glass.