A new discovery rock hounding, is it
possible? In the fall of 2023,
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Looky what I found |
I attended a Colorado Springs Mineralogical Society
(CSMS) Club sponsored field trip to one of
Joe Dorris’s claims. Joe is a local miner who
allows Clubs, by appointment, to prospect
his claims. I spent the morning prospecting
a hillside that many had dug before me. The
mineralization signs on the surface of the hill
looked promising. I reasoned that if others
had dug here, maybe there was something
someone had missed or overlooked. There were gemmy shards of quartz
and light blue/green chips of amazonite left
by others long ago. Some machine digging
had also been done. Mother Nature was
eroding away a bit of the side of one of the
machined pits. I decided to check the old
dig. The pit was about 6 feet deep. Near the
bottom of the pit-wall I noticed a bit of
yellowish clay. The yellow clay contrasted
sharply with the greyish/brown surrounding
scree. I stuck my pickaxe into the yellowish
clay and was soon in a thin seam of
microcline crystals. I began an adventure that
lasted a few days—could this be the Mother
Lode?
I followed the yellow clay seam until it
intersected with a larger formation of quartz
and formed a pocket of crystals. The pocket
was filled with smoky quartz crystals that
were covered with purplish clay.
Unfortunately,
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Purplish bottom of pocket still loaded with crystals |
the crystals were nearly all
broken and deeply fractured. A few single
microcline crystals showed a bluish tint to
them, so I knew I had amazonite.
I probably pulled out a couple hundred
quartz crystals that day, but only a few
crystals were collectible due to damage. I
decided to give this dig a name, and it will
hereafter be referred to as the Eclipse
pocket. I found the pocket a day before an
annular eclipse and came back to the dig a
day after the eclipse.
After cleaning out the large pocket I
retraced my excavation and followed some
quartz shards to my left. The broken-up
shards of quartz led me into a small, but
nicely formed pocket of gems. I got a few
complete smoky quartz crystals from this
pocket and a couple well-formed, albeit small,
amazonite smoky quartz combination
specimen.
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One of only a couple combos I found |
As I finished the day, I sent my good friend
Bob into the dig to see what he could find,
while I sorted and packaged my finds. Bob pulled out some fluorite and interesting
pseudomorphs. I was barely able to keep up
with what Bob was pulling out.
Pseudomorphs are minerals that replace
other minerals, taking on the original
mineral’s crystal form. The new crystal has
the form of the original. (See Twinning,
Polymorphism, Polytypism,
Pseudomorphism (tulane.edu)). I was finding
quartz in rhombic forms, suggesting to me
that the quartz was replacing a carbonate
mineral, maybe siderite? At the end of the
day, I showed Joe Dorris my finds. He was a
bit surprised by the odd pseudomorphs.
I returned a few more times to the site
with Joes permission and was
never disappointed. It seemed I would just
finish up one pocket of crystals when another
pocket showed itself. I believe there were 5
distinct pockets of crystals. Minerals in all 5
pockets were covered in a purplish clay.
While I was digging, as soon as I saw a
change of color (reddish brown to purple), I
knew I was coming into another pocket of
crystals.
None of the additional pockets came close in
quantity or quality to the crystals I found in
the first pocket. All the other occurrences
had amazonite, purple fluorite and
pseudomorphs of quartz after a carbonate. I
found very few smoky quartz crystals as I
progressed along the microcline formation/
pegmatite. It seemed like the higher up I dug
along the pegmatite, the more faded out the
amazonite became. Also, the purple color of
the fluorite diminished in intensity.
I made sure to show Joe my finds,
and he got a share of the minerals. I am a bit
stumped on the rhombohedron shaped
quartz pseudomorphs. I can’t be sure what
the original/replaced mineral was. Similar
drusy quartz also encrusted some of the
plates of amazonite, making epimorphs of
quartz over microcline. The largest unknown
is what kind of carbonate was dissolved and
replaced with quartz.
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Quartz w/ Fluorite ps carbonate |
“The most common
quartz pseudomorphs are those of calcite,
barite, fluorite, and siderite” (https://
www.mindat.org/glossary/
pseudomorphous_quartz). The common
theory among local diggers is that the original carbonate was most likely a siderite. I guess I
will go with pseudomorphs of quartz after
siderite for now. After finishing up digging out the Eclipse
pockets, my next project was to clean my
finds. The first step was to sort out all the
fluorites to clean separately by hand. Next, I
took the clay-enveloped minerals to a local
car wash for a good soak and spray. After
doing a secondary wash at home, I carefully
examined my specimens for quality—no
sense wasting time and energy cleaning
minerals that are chipped or broken. While
checking for quality I noticed some very odd
crystals. I am used to finding quartz,
microcline, fluorite, and goethite, but now I
was looking at something different. Time to
get out my microscope and take a closer
look. I had seen black rod-like minerals
before and reasoned this was columbite--Fe (see pic below).
Another mineral looked a bit like zircon.
After some consultation with subject matter
experts, it was determined that the suspected zircons are actually xenotime (see pic below).
Finally, I started cleaning the fluorite I set
aside earlier. While cleaning clay from the
fluorite, I realized that a piece I was cleaning
was not fluorite at all but appeared to be
barite (see pic below). The barite fluoresces and even
phosphoresces a light yellowish-tan under
long-wave illumination.
Time to check my reference book,
Minerals of Colorado, by E.B. Eckel, 1st Ed,
1997. Xenotime, an yttrium phosphate
mineral, referred to as xenotime-Y, was first
found by R.E. Ziegler in the Pikes Peak
Batholith. This was corroborated by E.E.
Foord and D.E. Kile (pg. 534). Columbite--Fe
or ferrocolumbite was first noted in Teller
Feb 2024 CSMS Pick & Pack 17
county by Lazard Cahn (pg. 161). L. Cahn
was the CSMS Club co-founder and is the
honorary Club president. Finally, barite.
According to a Ray Berry communique, small
well-developed barite were found associated
with smoky quartz, microcline, and calcite in
Teller County (pg. 92). No spectrographic or
XRF analysis was conducted on any of my
minerals. Long-time diggers and subject
matter experts of the Pikes Peak Batholith
helped me identify my finds.
On behalf of all the local Clubs, I wish to give
Joe Dorris a hearty thank-you for scheduling
and permitting Clubs to organize field trips to
his claims. Thank you also for allowing me
the extra time and pleasure to dig out and
finish a world-class pocket of minerals. Even
though it is now the middle of winter, I need
to contact our Club’s field trip coordinator up for
more fun during
the upcoming rock hounding season!
Black columbite rod in matrix/plate Xenotime crystals on matrix (magnified)
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Barite group |