Glass and supercooled liquid difference

[czr]

As the topic says, what's the fundamental difference?
What is the difference between amorhpous SiO2 and crystalline SiO2? - transparency? durability?

I need it to be explained in a short and simple words.

Thanks in advance.

 

[dik]

From Wiki...

https://en.wikipedia.org/wiki/Quartz

https://en.wikipedia.org/wiki/Fused_quartz

Dik