devitrifies

Devitrifies is the present tense form of the verb devitrify, used to describe a glassy or amorphous material undergoing devitrification—that is, transforming into crystalline phases. Devitrification is the broader process, while devitrifies refers to the action in a particular instance. The term is used in both materials science and geology to describe crystallization from an initially glassy state.

The mechanism involves atomic mobility that allows nucleation and crystal growth within an otherwise amorphous matrix. This typically occurs when a glass is heated into or near its crystallization range, or subjected to long-term aging at elevated temperatures. The specific crystalline phases that form depend on the glass composition and the thermal history.

In manufacturing, devitrification is usually undesirable for ordinary glasses because the appearance and properties can deteriorate: crystals scatter light, reducing clarity, and may alter strength or dimensional stability. However, controlled devitrification is exploited to create glass-ceramics, where a glass is deliberately heat-treated to produce a fine, dispersed crystalline phase within a glassy matrix. This approach can yield materials with improved toughness, thermal stability, or wear resistance. Common examples include lithium disilicate and other aluminosilicate glass-ceramics developed for specialty applications.

In geology, devitrification describes the natural crystallization of volcanic or obsidian-like glasses as they are buried or slowly altered in the crust. The resulting devitrified rocks show microcrystalline textures that record post-formation changes in temperature and pressure.