If you vitrify something, you turn it into glass or a glass-like substance. Glassmakers can vitrify sand to make glass.
Chemists study how substances change. One such extreme change is when a substance is vitrified, or turned into glass through heating and rapid cooling. Scientists can vitrify substances in the lab. Substances can also be vitrified in nature — due to a lightning strike, for instance. Vitrify is related to vitreous, meaning “glassy.”