Geodes
That makes sense.
The quartz does remain, infact you almost wonder where all the other material
went. The world is covered by quartz sand and quartz gravels. All over the
surface. This is what makes the theory of gravel and sands being formed by the
earth belching them out of large fractures that opened and then slammed shut so
attractive to me.
The overall theory can be attacked easily in small areas but it is the total
coverage of all these bits and pieces of not quite explained observations that
brings it home to me.
Kamron