A young man killed in the eruption of Mount Vesuvius in 79 CE was likely overcome by a fast-moving cloud of gas at a temperature of more than 500°C in a process that transformed fragments of his brain into glass,

In a nutshell Scientists discovered a human brain from 79 CE Vesuvius eruption transformed into glass—the only known case of natural organic glass preservation in history. The brain vitrified at temperatures above 510°C followed by extremely rapid cooling,

The hard skull and spine of the man—whose remains archeologists found still in his bed in the town of Herculaneum—likely protected the brain from complete thermal breakdown, allowing fragments to form into organic glass.