devitrification

Devitrification is the process of crystallization in a formerly crystal-free (amorphous) glass. The term is derived from the Latin vitreus, meaning glassy and transparent.

==Devitrification in glass art== Devitrification occurs in glass art during the firing process of fused glass whereby the surface of the glass develops a whitish scum, crazing, or wrinkles instead of a smooth glossy shine, as the molecules in the glass change their structure into that of crystalline solids. While this condition is normally undesired, in glass art it is possible to use devitrification as a deliberate artistic technique.