Zahoor Hussain,

Please specify your question. Microstructural mechanism of SiO2 is fairly ambiguous.

In terms of simulations, you can always look at a phase diagram, which will tell you tons of information on the thermodynamics of the system with temperature and pressure. There is much literature on this subject, which can be found with a quick Google Scholar search.

Kinetic studies are also possible with in-situ high temperature XRD and possibly thermodynamic studies if you are willing to wait for extended times. SEM gives you empirical information about the microstructure, however, it is ambiguous without further information from XRD or Raman spectroscopy.

Good luck!