If glass is a liquid, can it ever freeze?

[CanTak3]

First a Cecil topic:

http://www.straightdope.com/classics/a1_120.html

Next a question: Whether you consider glass an amorphous solid or a supercooled liquid, the simple fact is that it flows albeit extremely slowly. Can I cool glass to a point where it would finally gain crystalline structure and be considered a solid and only a solid? What temperature? Could I see through it? It doesn’t seem right that at absolute zero glass should still be on the threshold of liquid and solid.

[AndrewL]

Silicon dioxide in crystalline form is found as quartz and related minerals. I don’t know if glass can ever spontaneously crystallize into quartz; I suspect that once glass is cooled to the point of solidifying it’s pretty stable.

[tomndebb]

Actually, Cece’s answer (even the “corrected” later response) is not without its detractors:

Glass. What the hell is it!?
Glass - liquid or solid?

Those threads were in response to Cece’s column and were placed in the Comments on Cecil’s Columns Forum for that reason.
You seem to be using a point raised there to ask a different question, (making it a legitimate GQ thread), but I am directing your attention to those threads on the off chance that a point raised there may either answer or negate your question, here.

[Blake]

@CanTak3

Whether you consider glass an amorphous solid or a supercooled liquid, the simple fact is that it flows albeit extremely slowly.

That’s not true. Glass simply doens’t flow at all at normal temperatures. It’s solid in the sense that it is rigid and doesn’t take the shape of its container. It is only a liquid because of its molecular arrangement, not because of the way it behaves.

[vision80]

This is probably part of the reason why people think glass flows at room temperature:

http://www.physics.uq.edu.au/pitchdrop/pitchdrop.shtml

http://www.physics.uq.edu.au/pitchdrop/pitch_wide.jpg

http://www.physics.uq.edu.au/physics_museum/pitch1.gif

[picunurse]

Glass does not “flow,” as was once thought. The process by which ancient glass was made was by rolling, blowing and spinning the molten glass. That made the edges thicker than the center. Once cut, the glass was installed with the thicker end down for both esthetic (it looked top heavy or asymetrical otherwise) and practical (Less distortion in the thinner portion) reasons.

Conclusion

There is no clear answer to the question “Is glass solid or liquid?”. In terms of molecular dynamics and thermodynamics it is possible to justify various different views that it is a highly viscous liquid, an amorphous solid, or simply that glass is another state of matter which is neither liquid nor solid. The difference is semantic. In terms of its material properties we can do little better. There is no clear definition of the distinction between solids and highly viscous liquids. All such phases or states of matter are idealisations of real material properties. Nevertheless, from a more common sense point of view, glass should be considered a solid since it is rigid according to every day experience. The use of the term “supercooled liquid” to describe glass still persists, but is considered by many to be an unfortunate misnomer that should be avoided. In any case, claims that glass panes in old windows have deformed due to glass flow have never been substantiated. Examples of Roman glassware and calculations based on measurements of glass visco-properties indicate that these claims cannot be true. The observed features are more easily explained as a result of the imperfect methods used to make glass window panes before the float glass process was invented.