1) Become crystalline 2) Crystalise 3) Crystalize 4) Crystallize 5) Effloresce 6) Make brittle or opaque 
• (v. t.) To deprive of glasslike character; to take away vitreous luster and transparency from.
De·vit'ri·fy transitive verb To deprive of glasslike character; to take away vitreous luster and transparency from. 
[v] - become crystalline 2. [v] - make brittle or opaque
devitrify, devitrifying, devitrified 1. To change from a glassy to a crystalline state and become brittle and opaque, or to cause a material to do this. 2. To cause (a glassy material) to become crystalline and brittle. 3. With reference to a volcanic rock or to a particle; to undergo a change in texture from glassy to crystalline.
verb become crystalline