Vitreous blue AZURITE crystals on LIMONITE. The
greenish crystals are malachite.
Concentric growth pattern for these masses of AZURITE crystals.
Broken portions of BARITE crystals. BARITE has a
variety of colors but usually white to yellow. It is very heavy for a
non-metallic mineral.
This is a portion of a BIOTITE crystal. Even in
this photo you can see how easily it cleaves in one direction.
Calcite occurs in a variety of colors. It always reacts to HCl acid.
This piece of clear CALCITE displays the optical
property of double refraction. Notice the grid lines behind the CALCITE
are double images.
These are CALCITE crystals. Associated with the CALCITE are small,
metallic crystals of chalcopyrite.
This piece of CHALCOPYRITE has oxidized and
tarnished. The top left hand corner has been broken to show a fresh
surface. The luster of this fresh surface is definitely a brassy metallic
color. CHALCOPYRITE is basically pyrite with copper (chalco) in it.
It is this copper that allows it to tarnish to the many colors seen in this
photo.
Another piece of CHALCOPYRITE (only slightly weathered).
The blue "cement" that is holding this rock together is CHRYSOCOLLA
along with a little QUARTZ.
A sheet of Native Copper from the Ray Mine in Arizona.
Characteristic light colored crystals of DOLOMITE.
