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Outcrops of the
Proterozoic Harney Peak Granite (~1.7 Ga) exposed along the Needles Highway
northeast of Custer. Note the vertical
joints and their relationship to the “needles.”
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One of my early trips to
the Black Hills of South Dakota was during a summer camping trip with a couple
of college friends. We were getting
prepared for fall classes and “needed” a break from our summer of manual
labor. As usual, my father was not
overly pleased with my absence from work; however, we were 20 years of age with
borrowed IDs (well maybe that was just a dream since such action was illegal)
and wanted to head west and see bears and mountain lions and climb
mountains. We were all small town kids
and escaping a town of less than 400 persons and several dogs certainly was a
major priority. So, off we went ready to
hunt for Custer’s gold, and meet wild women (well maybe not wild but just any
females our age). After a couple of days
we sort of changed our failed priorities to better reflect realities,
especially of the “boy meets girl” project!
Anyway, upon reaching South
Dakota we spent some time in Badlands National Park and I became fascinated with
the “wildness” of the area and the numerous vertebrate fossils. Little did I know that in a few years I would
be tromping around the badlands trying to complete a graduate thesis. Upon
driving over to the Hills we took in the requisite tourist sites such as Mt.
Rushmore, a fairly sleepy national monument in those days, Reptile Gardens
(still there) and a place called the Cosmos Mystery Area. The Cosmos “was discovered in 1952 by 2
college boys looking for a place to build a summer cabin. When they
entered this area they experienced a slight unbalance which increased
considerably on entering the old house. The boys were interested and
camped on the place while they investigated the odd phenomena. They
decided that here was something of interest to the general public, so they
began to fix the cabin to make it safe and then developed the demonstrations
that you will experience on our guided tour” (www.cosmosmysteryarea.com). In other
words, there was money to be made from the gullible tourists, including three backwards
kids from central Kansas. We had a ball
at Cosmos and came back to camp, actually with a stop at a German Beer Garden, determined
to sketch out the whys and wheres of the paranormal experience---after all we
were smart college kids with a science background, and cold Coors beer will fuel
anyone’s imagination. If you are really interested
in the experience of Mystery Spots (and they are multiple localities in the
U.S.), check out the web site at www.sandlotscience.com.
Now, why in the world did my
mind bring up that long-ago experience at Cosmos of the Black Hills? My answer is that I was thinking about
preparing a small Blog offering on the mineral hureaulite, a hydrated manganese
phosphate (Mn,Fe)5(PO4)2. OK, so what. Well, hureaulite is “reputed to
be a kundalini stone... as the golden light it emits can move up from the base
and sacral chakras through the entire body, and stimulate the awakening of the
kundalini” (http://www.healing-crystals-for-you.com).
So, with my kundalini activated I was brought
to several “heightened states of mental functioning such as genius, creativity,
inspiration, revelation, mystical experience, and paranormal faculties of mind”(www.kundalinistones.blogspot.com). I am guessing that my kundalini revved my mystical
experience at Cosmos of the Black Hills those many years ago. Now, with my creativity in high gear, I need
to finish this posting!
As readers know, I have a
great love for the Black Hills and several Blogs are dedicated to the geology and rocks and minerals of
this Laramide (late Cretaceous-early Tertiary) mountain range. If any readers plan on exploring the Hills I
would suggest a really wonderful book entitled Guidebook to the Geology of the Black Hills, South Dakota (Lufkin
and others, 2009). Although somewhat
technical, the photos and the maps should excite any rockhound, and geologists
will sleep with it under their pillow in order to transfer information to the
brain.
The book covers many of
the old mines in detail, but one of particular interest is the Tip Top mine
near Custer. The pegmatite exposed in
the workings has produced at least 92 minerals, 12 of which call the mine their
type locality and seven of which are endemic to the TipTop. Mining for tin at the Tip Top commenced in
the 1880s but was a fizzle. In the first
half of the 20th Century the Tip Top was mined for various varieties
of feldspar and in the early 1980s beryl was produced (Lufkin and others, 2009). Today the mine is leased by Tom Loomis (www.dakotamatrix.com), one of the
authors of the geology book noted above.
The amazing “thing” about
the Tip Top, besides the 92 known minerals, is the large number of microscopic
minerals coming from the “?hydrothermally altered beryllium and phosphatic
rocks” (Lufkin and others, 2009)—it is a micromounter’s paradise.
I have a tenacity to pick
up minerals from the Hills if I see such offered by dealers (at a reasonable
price). A couple of years ago, when
perusing the smaller venues at Tucson, I nabbed a small specimen of the above
mentioned hureaulite [(Mn,Fe)5(PO4)2(HPO4)2-4H20]
collected at the Tip Top. At least I
believe it is hureaulite as well as some other unidentified minerals!
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Red to pink hureaulite
from Tip Top Mine. Length of largest
mass ~9 mm.
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Although hureaulite can
appear in a number of colors—red, many shades of white, brown, yellow—pink to
red seems to be the dominant color (i presume manganese is the chromophore). Although
some specimens display nice crystals---see MinDat---others are composed of
compact masses of indistinguishable crystals.
They range from transparent to translucent and are quite brittle (know
from experience). The hardness is ~5
(Mohs) and the mineral displays a less than vitreous to greasy luster.
MinDat notes that
hureaulite is associated with triphylite and is probably a secondary weathering
product of the mineral. Triphylite is a
fairly common lithium iron phosphate in solid solution with lithiophylite, a
lithium manganese phosphate. Both, along
with the common apatite, are primary phosphates crystallizing from late stage
magmatic solutions. Hureaulite is a secondary
mineral forming in low temperatures from the oxidation (weathering in the
presence of water) of the primary minerals.
It seems as if water removes the lithium from the primary minerals and
leaves behind the iron and manganese.
So, a long ago college
trip to the Black Hills was the initial stage of my fascination with the
western part of South Dakota. I did not direct my life. I didn’t design it. I never made decisions. Things always came up and made them for
me. That’s what life is. (B.F.
Skinner)
REFERENCES CITED
Lufkin, J.L., J.A. Redden, A. Lisenbee, and T. Loomis, 2009, Guidebook to the Geology of the Black Hills, South Dakota: Golden Publisher, Golden, CO.