February has rolled around again,
and the month is special for Groundhog Day, Valentine’s Day, A. Lincoln’s and
G. Washington’s birthdays rolled into President’s Day, Chinese New Year (2020
is the Year of the Pig), and the Tucson Rock and Gem Shows. Of course, the latter is my favorite although
I certainly respect the birthdays of our most famous presidents.
The Tucson shows occupy the first
two weeks of February and culminate in the official Tucson Gem and Mineral Show (known
as the main show) that is held in the downtown Convention Center on February
14-17. Scattered around town are nearly
50 other “official” shows and venues.
Some of the ancillary venues are quite large with hundreds of dealers selling
their minerals, rocks, fossils, coon tail hats, lotions better than Botox, and
a wide variety of “you name it.”
However, most of the venues are related to geology, except perhaps the African
Village.
In addition to the large venues
there are many smaller shows with perhaps a dozen or so dealers. However, small does not always relate to less
expensive minerals and rocks---some are very high end such as the Westward Look Mineral Show.
My first day at the "Show" (refers
to any of the venues) was on Monday the 4th since I arrived in town
somewhat “late.” On that particular day
I had planned to hit a couple of outdoor shows where sellers are dealing out of
small popup tents, or small RVs, or whatever but the tables are exposed to the
elements ( I refer to them as mom & pop shows). From what I understand this is how the
smaller ancillary shows started out decades ago, before the advent of tents as
large as a football field. Monday was also the day it decided to intermittently
rain and I was soaked more than once. I
felt rather sorry for the dealers, but most come back year after year and just
take the weather as it comes.
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· When I first attend the Tucson shows there were many of the
ancillary venues that looked like this---put out the tables, maybe a popup
cover and have your camper parked behind the goodies. Unfortunately, most of the mom and pop shows
have disappeared from the scene.
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This was a
fantastic specimen as it is a polished slab of a phosphate nodule collected
from near Lucin in northwestern Utah. The green is variscite, while the
gray is is probably wardite, and others are too small to identify. It
resembles those nodules from the Little Green Monster Mine once operated by Ed
Over and Art Montgomery.
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| When the rains come, cover the mineral specimens and
let the honker rocks get wet. Maybe they
are yard rocks anyway. |
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Can’t get away for lunch? Fire up the propane cooker.
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Want to guard you wares at night?
Don't want to spend your small profits? Pitch the tent with a rain guard.
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The Miner’s Coop is one of the
first shows that visitors might see coming in from the north on I-10; however, it is
one of the most difficult to reach as the two major exits have been closed for
at least 2-3 years due to construction.
On my visit the crowd was sparse as the rain and mud put a damper on the
selling and dealers were playing a cat and mouse game of pulling off tarps to
expose their goodies and then covering the tables to try and keep them somewhat
dry. I did talk to Kim and Bodie (with
their amazonite and quartz) from the Lake George region, a seller from Fountain
and one from Pagosa Springs. I really
did not see all of the specimens available, due to covered tables, and so moved
on without a purchase.
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Blue crystals of rare boleite, a
complex, hydrated lead-silver-copper oxychloride offered by Jack Crawford.
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My second stop, Mineral and Fossil Marketplace, is also a favorite of mine
mainly due to the presence of a dealer by the name of Jack Crawford. Now Jack does not know me from the man in the
moon but does recognize me from past years and if questioned, regales me with
stories from his many years of collecting in Mexico. He is a great person to visit with and
someone with a terrific knowledge of geology, especially mining and minerals.
He also has some of the finest crystals of boleite (hydrated lead-silver-copper oxychloride). I have purchased some smaller
crystals in past years as they are rather rare; however, this year he had much
larger crystals and therefore out of my price range (see Posting June 22, 2016).
The second reason for a stop was
to admire the wares sold at Australian Outback.
Now, I am not a collector of “slabs” or lapidary rough but do like to
ogle the nifty displays from Australia.
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| I always enjoy Australian Outback’s display of siliceous mookaite. The rock is collected from the Windalia Formation (Cretaceous) in western Australia and is actually a radiolarite (according to MinDat) where the silica originated from ginormous numbers of single celled organisms called radiolarians. These little creatures have a “skeleton” of opal (form of silica). However, Australian Outback believes that water percolated through a radiolarite and deposited silica, often in the form of chalcedony rather than opal, in overlying layers and during the way picked up iron oxides for color. |
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Tent at Australian Outback keeping
rain off the valuables at Mineral and Fossil Marketplace.
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These nicely polished, shiny slabs
are marketed as Black Jade. They are an
amphibole and a form of the mineral actinolite, a calcium-magnesium-iron
silicate. Nephrite is also an amphibole and is one of the two minerals commonly
called green jade. So, is this
jade? Don’t know as it could be nephrite
included by black minerals. I assume Black Jade
is a trade name.
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I had always seen kunzite, a pink spodumene
or lithium aluminum silicate, as nice gemmy pink crystals used as faceted
gemstones. These slabs are marketed as
such and are also sold as polished cabs.
I could not locate other information.
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This petrified wood is marketed as
peanut wood. The wood has a dark color with numerous infilled white borings due
to a marine boring clam called Toredo.
A geode with inner celestine
crystals offered by a Madagascar dealer.
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I also was able to nab a specimen of wulfenite collected from Utah and was interested in the specimen for a couple of reasons. First
of all, wulfenite is the theme of the Tucson main show this year (Wulfenite is
Loved) and second, I have an interest in minerals from Utah. In addition, both Rock and Gem and Rock and
Minerals devoted their recent journal editions to the mineral and forgot to
mention collecting from Utah!
Wulfenite is probably one of the
most easily recognized mineral among any amateur rock hound and one of the most
collectable by hobbyists from all ranks, newbie to professional (7206 photos on
MinDat). It is a beautiful mineral and easily adorns specimen shelves across
the collecting community.
A lead molybdate [Pb(MoO4)],
wulfenite is famous for its common habit of forming thin tabular crystals,
often transparent (but ranging to opaque), that occur in various shades of
orange to red to yellow (uncommon as green or brown or blueish or black (see
Posting April 20, 2017) and “butterscotch” is a common color descriptor. There is some disagreement about the color
changes although minor chromium probably acts as a red or yellow
chromophore. Crystals often have a
vitreous luster and will easily reflect light as a mirror. Others are much “duller” and have a resinous
luster; some are covered by various druzes. The streak is a nondescript
white. Wulfenite is quite soft at ~3.0 (Mohs) and the crystals brittle. Besides the thin tabs, pyramidal (and
bipyramids) and stubby crystals are common and often confuse new collectors who
are used to orange or yellow tabs.
Wulfenite is a secondary mineral
deposited in the oxidized zone of lead ores;
it seems particularly common in the state of Arizona and Bladh (2019) noted at
least 275 collecting localities. Although
collectors love isolated and single crystals the vast majority of wulfenite probably occurs as granular or
intermixed masses.
Wulfenite is much less common in
Utah, than Arizona, and therefore “finds” at shops or mineral shows are
exciting. My particular specimen (shown above with crystalline calcite, width ~4.0 cm) picked
up from this show was collected at the Tecoma Hill locality in Box Elder
County, an area in the extreme northwest region of the State and former sites
of lead-zinc-molybdenum exploration. Most of the ore seems associated with Tertiary igneous rocks intruding Paleozoic limestone.
Note August 2020: The specimen could have come from Nevada as the workings are right on the state line. The ore minerals are mainly argentiferous cerussite and a few small
pods of residual galena. Museum specimens of wulfenite on calcite were
found in the upper workings of the Jackson(?) mine (https://pubs.usgs.gov/of/1976/0056/report.pdf
REFERENCES CITED
Bladh, K., 2019, Arizona Wulfenite: Rocks and Minerals, v. 94, no. 1
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