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,

The only known case of a human brain being turned to glass, that of a man caught in the 79 AD eruption of Vesuvius at the Roman town of Herculaneum near Pompeii, has been solved. The man's brain turned to glass due to the extremely rapid cooling that ensued after a white-hot cloud of ash engulfed him,

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.