vitrifying

Verb

vitrify (third-person singular simple present vitrifies, present participle vitrifying, simple past and past participle vitrified)

1. (transitive) To convert into glass or a glass-like substance by heat and fusion.

   Synonyms:

   glassify

2. (intransitive) To be converted into glass, especially through heat.
   • A large percentage of all Late Horizon fragments at this site was overfired, to the point where many were vitrified, black to dark brown, and misshapen, some with blistered surfaces.1976, Dorothy Menzel, Pottery Style and Society in Ancient Peru: Art as a Mirror of History in the Ica Valley, 1350–1570, Berkeley, Calif.: University of California Press, →ISBN, page 30