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| WENDOVER WILL, ALL ~65 FEET WITH A MECHANIZED WAVING HAND, BECKONED VISITORS TO THE STATE LINE CASINO IN WENDOVER, NEVADA. AFTER 120 MILES OF BONNEVILLE SALT FLATS UTAHANS WERE READY FOR A LITTLE ACTION AND AN ADULT BEVERAGE. PHOTO COURTESY OF WENDOVER HISTORY |
Gold Hill is one of those classic collecting areas
for Utah rock hounds, and those others pilgrims willing to travel to the far western
reaches of that fine state.
Of course, the bi-state town (Nevada-Utah) of Wendover is on the route if one is interested
in mining recent gold or needing a motel room and an adult beverage.
In the “old days” I had a research area down west of
the Deep Creek Mountains to the south of Wendover and my crew always wanted to stop at the
casino for a “good meal”. They seemed
not to really like my cooking campfire meals down in the desert! So, it was off to the Stateline Hotel and Casino (currently operating as the Wendover Nugget Hotel and Casino),
home of Wendover Will. Seems like a entrepreneur
by the name of Bill Smith operated a gasoline station in Utah (right east of
the state line). Never one to miss an opportunity, when gambling was
legalized in Nevada in 1931 Bill added a casino across the state line! During the years that I was stopping in for a refreshment before
heading to the desert, the vehicle was parked in Utah, we crossed a white
painted line, and voila---we we in a different world with Wendover Will welcoming all.
Leaving the world of bright lights and tinkling slot
machines behind we heading south but often could not resist a side trip to
the old mining town of Gold Hill, Utah. I
previously wrote about the mines and collecting conichalcite, a bright green
copper calcium arsenate hydroxide, [CaCu(AsO4)(OH)]---see that blog
on December 8, 2011. The information sign at Gold Hill notes that the usual
gold, silver, copper and lead were initially mined but when those minerals
became depleted, the boom was over and the town became a ghost. During
World War I, arsenic was in demand as insect control for creatures devastating
the cotton fields of the southern U. S. So, Gold Hill opened up again and
mined arsenates.
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| COLORLESS AND VITREOUS ADAMITE CRYSTALS ON LIMONITE. SPECIMEN IS 4.3 CM WIDE. |
Another mineral that Gold Hill is “famous for” is adamite,
a zinc arsenate hydroxide [Zn2 (AsO4)(OH)]. Adamite is one
of those minerals that usually occurs in the oxidized or secondary mineralized zone
where zinc is present, and arsenic was in the hydrothermal solution.
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| MODIFIED ORTHORHOMBIC AND COLORLESS CRYSTALS OF ADAMITE. INDIVIDUALS ARE .5MM OR LESS IN LENGTH. |
Most of the Gold Hill adamite that I have seen is composed
of very tiny crystal druses or ball-like clusters that are either yellow or
various shades of green in color. It
appears that either iron or copper make some element substitutions. However, pure adamite is colorless,
transparent and quite vitreous. In fact, I paid little attention to my specimen of
ademite from Gold Hill since I thought it was just “sort of a pretty” rock with
numerous tiny quartz crystals. But, much
to my amazement, under high power of a binocular microscope those tiny crystals
(mostly modified orthorhombic) turned out to be colorless adamite. Some may have hints of very pale green but
with my color blindness, it is hard to tell!
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| A VUG IN THE SPECIMEN CONTAINING AN UNKNOWN SPRAY OF MINERALS. THE LONGEST INDIVIDUAL ROD IS ABOUT .5 MM. |
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| CLOSE-UP PHOTOMICROGRAPH OF UNKNOWN MINERAL. ANY IDEAS? |
I tried to find other associated minerals in my small specimen,such as austinite,
but no luck. However, there are tiny mammillary
structures that are either goethite or limonite, perhaps ?pseudomorphs after
smithsonite. And, there are a few sprays of an unknown mineral present!
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| PHOTOMICROGRAPH OF TINY MAMMILLARY STRUCTURES OF GOETHITE OR PERHAPS LIMONITE. ARE THESE PSEUDOMORPHS AFTER SMITHSONITE? |
I just need to revisit Gold Hill and do some dump
digging; however, it is a fair trip from the Springs and with the price of
diesel….! But wait, all I would need is
a couple of lucky pulls on the machine :)
mike
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| CARTOON OF MODIFIED ORTHORHOMBIC CRYSTALS COMMON TO ADAMITE. |
