Sunday, March 1, 2020

TUCSON: PUEBLO--CAMPYLITE AND WULFENITE AND HAPPY DAYS



West across the Interstate from the 22nd Street Show is the Pueblo Gem & Mineral Show/Ramada by Wyndham.  This is a very large Show scattered among motel rooms, large tents, small tents and many other structures. By my count there are approximately 275 vendors ranging from metaphysical, beads, fossils, wholesale jewelry, retail jewelry, giant quartz crystals, opals, rocks and minerals, etc. etc. This was one of the last Shows I visited, and the displays seemed to be like the movie Groundhog Day, seen it all before!  But, I did have a good time wandering around and was able to locate a few crystals, and visit with a few nice dealers.

The parking was pretty crappy at the Show.  We paid our $10 (expensive) and were directed to the far away dirt/dust parking area.  A golf cart did come along and haul us, thru massive dust, over to the dealers, including the massive quartz crystal.  I felt sorry for the drivers, some of whom wore masks. Wonder if Mr. Rockhounding the Rockies has ever dug up a crystal like this at his claim near Lake George?

How would  an ole rockhound haul a quartz specimen like this home?

How about this carved couch.  Not very comfortable but it was marked sold.

Lots of magic minerals were on display at a number of dealers.  About the only magic mineral I have faith in is gold.

I did notice several vendors who displayed some nifty carvings.  However, not everything marked jase is really "jade."
Surprise, surprise! And there were beads!

One of my favorite dealers, with a nice friendly staff, is Korite International based out of Calgary, Alberta, Canada. The company mines the gemstone ammolite from the Cretaceous Bearpaw Formation exposed along the St. Mary River.  Ammolite is a biogenic gemstone and is composed of material (nacre) that is found in the shells of large coiled mollusks termed ammonites.  Nacre (also found as mother-of-pearl and pearls) is made of the carbonate mineral aragonite (CaCO3).  The microstructure of the aragonite reflects light and produces an opal-like iridescence. This type of display is very rare as most aragonite in ammonites is unstable and at other localities has been replaced by calcite or perhaps pyrite.

My first stop was at a small motel room as we were wandering through.  Just some small displays but the two young men selling were very nice and this was one of their first shows as a vendor.  They had come from North Carolina and had spent the previous month stopping at localities collecting this and that getting ready for shows this spring and summer along the east coast. They decided to sell at Pueblo since the space was abandoned by a previous seller and they received a “good deal” on the lease.  I was their first customer and they showed me a flat of wulfenite collected from the La Morita Mine, Ascención Municipality, Chihuahua, Mexico.

I am pretty much a sucker for wulfenite, a colorful lead molybdate [PbMoO4] appearing as thin tabular crystals.  The theme of the 2019 Tucson Show as wulfenite and last year I offered several Blog Postings on the mineral---no need to repeat mineral info here. The specimen from La Morita also has some nice yellow botryoidal crystal masses of  the lead chloroarsenate, mimetite [Pb5(AsO4)3Cl].  According to MinDat, this small polymetallic (mostly lead, zinc, and silver) mine started producing these lustrous crystals wulfenite-mimetite crystals (both secondary minerals) in 2018 & 2019.

A really nice cluster of wulfenite crystals on a barite matrix with several "balls" of microscopic crystals of mimetite perched on the wulfenite in the upper left quadrant.  Width FOV ~2.1 cm.
Speaking of mimetite (which I am to myself), campylite is a variety of mimetite where the distorted crystals have a barrel-shaped bend (they are very distinct).  This variety of mimetite is rather rare and the best-known specimens come from the Dry Gill Mine, Caldbeck, Allerdale, Cumbria, England, UK.  From what I read the burnt-orange colored campylite crystals from Dry Gill are one of the “Classic Minerals of England...and one of the most famous mineral localities in the world” (Cooper and Stanley, 1991).  Little did I know this as I shelled out three bucks for the specimen---not bad for a “classic.”


Views of campylite crystals.  Width FOV upper~1.8 cm.
Cooper and Stanley (1991) further described the Mine as of little commercial interest with few minerals in the vein, and only a few hundred tons of colored lead ore had been removed before operations ceased in 1860.  Mineral specimens are increasingly hard to find with a few being obtained in the 1970s.  Campylite, [Pb5(AsO4)3Cl] is a secondary mineral found in the oxidized zones of lead deposits, such as galena that is present at Dry Gill.  In addition, Cooper and Stanley (1991) noted that campylite is a “phosphatian mimetite.”  Since mimetite, lead arsenate, is in solid solution with the lead phosphate pyromorphite, I presume that phosphatian campylite is on that line leading to pyromorphite.


REFERENCES CITED

Cooper, M.P. and C.J. Stanley,1991, Famous mineral localities: Pyromorphite group minerals from the Caldbeck Fells, Cumbria, England: Mineralogical Record v.22, no. 2.

A Happy Day is a day when I hit the bed with a sense of satisfaction for the day well lived at a rock, mineral, and fossil show.   (apologies to Jagadish).

Thanks to Scott Adams and Dilbert.com.

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