Quartzite rock is rich on quartz.
But it is not formed
from pure quartz alone.
It's most often formed
from sandstone, which however contains a lot of quartz.
The sandstone needs to
be buried, heated and squeezed in moderate pressures but high
Other minerals in this
rock inclue mica, sillimanite and kyanite.
It has medium texture, conchoidal fracture, and is a very brittle and