vitrified

Converted into glass; hence, by extension, partially converted into glass, as having the exterior converted into a glaze, or having the substance hard aud glassy from exposure to heat: as, vitrified tiles.

Converted into glass.

Simple past tense and past participle of vitrify.

Converted into glass

(of ceramics) having the surface made shiny and nonporous by fusing a vitreous solution to it