2
$\begingroup$

Since glass is amorphous quartz and when you slow the cooling of something enough it will crystallize, couldn’t you melt $\ce{SiO2}$ (sand) and then very slowly cool it to cause spontaneous nucleation and form quartz crystals?

If so, then why hasn’t it been used before? It would seem to be a better method than flux because in flux you need many chemicals and a dissolving chemical or mix and it is a complicated and very long process to grow very small crystals throughout the whole mix. If you simply cooled a molten mixture slowly enough to cause complete crystallization, then the entire mix of molten crystal would need to form crystal because it all is cooling down.

Improve this question
$\endgroup$
6
  • 1
    $\begingroup$ About the second part of your question, both the α- and the β-phase of quartz have what we call an enantiomorphic space group. It forms spirals that can be 'enantiomers' to each other, which I guess also gives it its properties. For many applications you often need the pure enantiomer which will grow in a seed of the correct orientation under for example hydrothermal conditions. $\endgroup$
    – Justanotherchemist
    May 27, 2019 at 8:27
  • $\begingroup$ Melting and cooling will give you a bunch of crystals lumped together. Why would you want that? Then again, I've seen single crystals of quartz as big as a tabletop, and they were not made by melting. $\endgroup$
    – Ivan Neretin
    May 27, 2019 at 8:29
  • $\begingroup$ see eg ndk.com/catalog/AN-SQC_GG_e.pdf $\endgroup$
    – Buck Thorn ♦
    May 27, 2019 at 8:47
  • $\begingroup$ In principle, maybe. But that isn't how big crystals are formed in nature. Most deposit from solutions not from melted pure silica. $\endgroup$
    – matt_black
    May 27, 2019 at 13:03
  • $\begingroup$ @NightWriter Your example post is about hydrothermal growth of a crystal. $\endgroup$
    – Buttonwood
    May 27, 2019 at 21:37

0

Reset to default

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.