Nearly 2,000 years ago, a young man's brain in Herculaneum turned to glass during Mount Vesuvius' eruption, due to extreme heat and rapid cooling. Scientists discovered this unique transformation in 2018,

Mount Vesuvius was so hot it turned a man’s brain into glass when it erupted, fascinating new research shows. A piece of dark glass was found in the man’s skull, who died in the Roman city Herculaneum almost 2,

It was a surprising discovery when scientists examining the remains of a man who died in bed in the ancient city of Herculaneum after Italy's Mount Vesuvius erupted in 79 AD found dark fragments resembling obsidian inside his skull.