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.

Mount Vesuvius erupted in 79AD, covering nearby Pompeii and Herculaneum in ash which buried the towns and hundreds of its residents which left them perfectly preserved