More forms of Quartz

This is part of the wall of an open geode.

Everything you see is some sort of silica.

All the crystaline silica is good old quartz, smoky quartz, which looks white at the fim itself. Further in, is a rim of greyisn smooth
chalcedony.

The rim itself is probably a mix of chalcedony
with microcrystalline quartz, and a tad of
opal mixed in for good measure. Love the
way it grew in cloudlike form as it filled in
the vug in the lava.