Vitrification (from Latin vitrum 'glass', via French vitrifier) is the full or partial transformation of a substance into a glass,[1] that is to say, a non-crystalline or amorphous solid.
In terms of chemistry, vitrification is characteristic for amorphous materials or disordered systems and occurs when bonding between elementary particles (atoms, molecules, forming blocks) becomes higher than a certain threshold value.
One study suggests[5][6][7][8] during the eruption of Mount Vesuvius in 79 AD, a victim's brain was vitrified by the extreme heat of the volcanic ash; however, this has been strenuously disputed.
As vitrification proceeds, the proportion of glassy bond increases and the apparent porosity of the fired product becomes progressively lower.
Vitrification can also occur in a liquid such as water, usually through very rapid cooling or the introduction of agents that suppress the formation of ice crystals.
[19] Ordinary soda-lime glass, used in windows and drinking containers, is created by the addition of sodium carbonate and lime (calcium oxide) to silicon dioxide.
Without these additives, silicon dioxide would require very high temperature to obtain a melt, and subsequently (with slow cooling) a glass.
According to the Pacific Northwest National Labs, "Vitrification locks dangerous materials into a stable glass form that will last for thousands of years.