Why does't amorphous silicon oxide present piezoelectricity?

[Silicon]

We know quartz,viz. crystal silicon oxide is a kind of piezoelectric solid.Does the amorphous silicon oxide present piezoelectricity also. If not,Why?
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I'm not good at English, so if there is any language errors in my threads please point them out. thanks very much!

[Claude Bile]

Amorphous silicon dioxide does not have the requisite crystal structure.

http://en.wikipedia.org/wiki/Piezoelectricity

Claude.