Sunday, February 9, 2020

NEWS FROM TUCSON; 2020 SHOWS HAVE STARTED


The time has come—Tucson 2020.  According to advertisements there are 51 different show venues this year with the culminating Tucson Gem and Mineral Show®, the main show, running February 13-16 at the Convention Center downtown. Smaller shows “officially” started Saturday January 31 although my dealer friends tell me that high end trading and buying in hotel rooms started much earlier.  In fact, some collectors of fine minerals had left town by February 1.  However, I am just an ole rockhound from Colorado Springs and happy to be here in the sunshine talking to the friendly, often mom and pop, dealers, and frugally buying a few goodies that light up my eyes.  Life is good.


After arriving in town, I started my wandering on Monday the 3rd and was able to hit a couple of venues in the afternoon.  My worn-out legs will simply not allow me to wander aimlessly so I pick my shows carefully where some of my favorite dealers reside, and where I am able to see some interesting specimens.
There are 1 million, 497 thousand and 642 carved Moroccan Orthoceras cephalopods for sale at the various Tucson venues.  They are only exceeded in number by strings of "beads" (below).

Although I am not into collecting fossils at this stage in my life, I enjoy seeing nice  vertebrates (clones) and invertebrates collected from private lands.  The molding and casting processes get better each year, and the prep work on some of the invertebrates is fantastic.  I generally stay away from Moroccan fossils since so many of them are repaired, carved and painted, and are simply unauthentic.
Small fish from the Green River formation in western Wyoming (Eocene) dwarfed by a large Xiphactinus from the Smoky Hill Chalk (Cretaceous) of western Kansas.
Marine reptile from Morocco. Is it "real"?  Don't know as I did not examine closely.  I do know that Mosasaur "jaws" complete with a row of teeth are for sale everywhere in the shows.  Most are composites.

One of the nifty places to see nice fossils and clones is the Mineral and Fossil Marketplace on North Oracle. Leon Theisen of Custom Paleo out of Ardmore, Oklahoma, has a fantastic collection of Devonian and Ordovician invertebrates collected from his two privately owned quarries.  He also has a magnificent amber barite from the Pierre Shale along Elk Creek that he collected several years ago (see my previous post on the barite).  He is always willing to spend time with visitors spinning a yarn or two.

Minerals and rocks by the flat, bucket or individuals are "for sale" by the "mom& Pop dealers.  Many have very nice specimens for the buyer.
Next door to the fossils are several “mom & pop” booths selling a variety of minerals.  At the time I visited, the vendors were trying to tie down and protect their tents from being destroyed by a nasty wind.  I also missed Jack Crawford at his usual spot. Jack, formally from Colorado but now from Silver City, New Mexico, was a great source of information on Baja minerals and always willing to share information.  His neighbor said he evidently sold his business and moved on. 
Trilobite from Custom Paleo in Oklahoma.
Down (south) Oracle a half block is an amazing store called Superb Minerals, 12,500 sq.ft. of the nicest zeolites one can observe—anywhere.  These minerals are from the Deccan Plateau in India and are found in concretions, GIANT concretions.  One can purchase Indian zeolites in about any rock shop or show and different minerals are very showy and quite reasonable in price.  However, these concretions are spectacular, and some could set you back $75,000 or more.  But they are nice. 
Zeolites and more zeolites.



The above three photos show the giant concretions containing a variety of zeolite minerals.  The floodlight is approximately 6 inches in diameter.
So, what was I able to snatch at the mineral booths? For starters I shelled out a whole two bucks for some small wulfenite crystals.  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) and “butterscotch” is a common color descriptor.  Wulfenite is Loved was the theme of the 2019 Show so why pick some a specimen this year?  The main reason is that the specimen was collected from the Old Yuma Mine, a polymetallic producer not located near the town of Yuma, Arizona, but situated just on the west outskirts of Tucson in the volcanic Tucson Mountains.  The Mine operated, sporadically, between 1916 and 1947 but was never a large metal producer; however, it did yield spectacular specimens of wulfenite and vanadinite.  Notice I used the past tense “did yield” since it was gobbled up by Saguaro National Monument, and since collecting is not allowed on USNPS lands, there will no longer be “fresh” Old Yuma Mine specimens floating around.  I just want to have a specimen from that rather famous locality.
Blades of wulfenite from Old Yuma Mine.  Width FOV ~1.4 cm.
For the same reason, I just want it, another two bucks bought me a crystal of idocrase (AKA vesuvianite) from the Fushan Mine in Hebei Province, China. Vesuvianite has a very complex, at least for me to understand, chemical formula and interestingly contains both neosilicate (SiO4 with a silicon anion and one tetrahedron) and sorosilicate (Si2O7 with two tetrahedra) groups:  Ca10(Mg, Fe)2Al4(SiO4)5(Si2O7)2(OH)4.   The nicest specimens (and I have not seen many) that I have observed are green in color, but specimens also might be brown to yellow to even a nice blue-purple in color.  If in crystals, they are usually prismatic and “eight-sided” with one set (of sides) being quite dominant so the prisms look square in cross section.  They are commonly terminated with a four-sided pyramid.  Vesuvianite is a fairly hard mineral at ~6.5 (Moh’s) with a vitreous to “greasy” luster.  Gemmy vesuvianite is transparent to translucent while other specimens are less than translucent (not quite opaque but something).

Tough to get good photos of a greenish termination of a "squat" vesuvianite crystal. The termination is a four sided pyramid with a flat top.  The numbers represent Miller Indices and are included to better observe the crystal faces.  In the center of the flat top is Axis C running "down" through the crystal.  The A and B axes run from side to side.  The "square looking" crystal is ~1.8 cm in size.
There were a few other purchases, but descriptions will come later.  

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