Roger Weller, geology instructor
[email protected] copyright 2011-R.Weller
agate from Africa
Agate is a form of cryptocrystalline quartz. "Crypt"
means hidden and the crystals
making up agate are submicroscopic in size,
definitely hidden from view. Agate is
the form of cryptocrystalline quartz
that displays banding. The bands may be thin
or thick and may vary
dramatically in color due to the presence of iron and
manganese oxides.
quartz-agate
africa14
Photo is copyright free for
non-commercial educational uses.
Just credit photo to R.Weller/Cochise College.