Railroad Pass, Clark County, Nevada (first RR Pass page here)

More info on RR Pass at my rockhounding site linked below:
https://southwestrockhounding.com/2020/04/02/more-on-railroad-pass-clark-county-nevada/

March 31, 2020

Yesterday I returned to Railroad Pass (internal link) to further investigate the area. I went before to look for andesite and to simply look the ground over. I was very disappointed not to find any quartz and I wasn’t planning a quick return. It turns out, however, that there is a mad history of failed gold mining on that hill. As a Gold Guy first and foremost, I knew I was going back as soon as possible.

To get to the good stuff first, I did find one rock with quartz. The quartz has the slightest blue tinge which shows poorly here. Never-the-less, I have my quartz. Gold is hosted in dozens of kinds of rocks without quartz, still, it’s the mineral I look for first. Yet it wasn’t what the most prominent prospector and geologist was looking for.

A well respected geologist named Robert T. Hill (1858-1941) became obsessed with the association of a mineral called alunite and gold. This rock building mineral was present with gold at the big Goldfield strike around the turn of the century. Hill developed this idea that if he could find a geologically similar location to Goldfield that also contained alunite, well, he’d be rich. You see where this is going.

Gold fever infects the best of minds, leading common sense astray even in people who should know better. For years he researched the hills of Nevada until he found Railroad Pass. Which went under a variety of names originally, most especially Camp Alunite, or just Alunite. This potash mineral had value by itself and was eventually mined in the area for the mineral alone.

Hill maintained that he found gold here and some other prospectors said they did as well. Yet I can find no records of production. Ordinarily, this would be the stuff of a mining company selling shares on hope and chicanery, promoting the view of a well-known geologist stating that gold was present. Yet Hill did not sell shares. Instead, apparently, he lost most of his personal fortune in this endeavor, along with that of his family, something over $200,000 before he admitted failure. That is really bad gold fever.

His workers sunk at least five shafts into that insanely hard rock. These shafts have since been backfilled to keep equally crazy people from falling to their deaths.

To be fair, other prospectors were working Railroad Pass before Hill arrived but they were few and, again, no results of production. Just assay results thrown about. Gold in “small isolated veins.” And Hill did have the germ of an idea, as alunite is regarded as an indicator of hydrothermal gold deposits, gold which is precipitated from water heated by magma. But Hill went way overboard comparing this ground to that of Goldfield, thinking that if he just mined deep enough he would find his El Dorado.

In any case, this kind of doomed, gold based behavior is very attractive to me. As a prospector I am interested in finding out whether any gold actually exists on that hill. There are also other things going on there, the area is so complex geologically that I could use it as a teaching hill. Who knows what I will find? Yesterday, though, my left leg gave out after only two hours. With my wrenched back I can still hike but I can’t carry much weight. Photos below.

In my previous post (internal link), I showed photographs of this multi-colored hill with little vegetation. Yesterday I took some samples from two of the colors. Today, I got out my hand rock crusher, my mortar and pestle, and am preparing to grind down the material. Then the pan out. For these odd looking rocks and soil I think a chemical test would be best. But I don’t know how to do those and I don’t know what I would be looking for. As a Gold Guy, when in doubt, pan it out. That’s a finishing pan, by the way, about ten inches across.

Update: That tan material might be decomposed granite or what we in the landscape trade used to call d.g. It’s commonly used for footpaths and small outdoor seating areas. It compacts well and doesn’t get muddy if put down correctly. It feels just like the d.g. I used to use. Mining granite for aggregate goes on across the highway, this entire Railroad Pass area described as a “granite pluton.”

Clark County image from the:

Index of Granitic Rock Masses in the State of Nevada By FLORIAN MALDONADO, RICHARD W. SPENGLER, W.F. HANNA, and G.L. DIXON
Prepared in cooperation with the U.S. Department of Energy
A compilation of data on 205 areas of exposed granitic rock masses in Nevada
U.S. GEOLOGICAL SURVEY BULLETIN 1831

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All sorts of rocks here, including what I think is porphyritic rhyolite. Nothing lights up under my lamps and no “U”.

What appears to be a backfilled shaft. Frustratingly, I didn’t see what I would consider waste or tailings from the shaft. Unless that quartz I found came from down below. That lone hunk of quartz was immediately below this small pit.

Another look.

More craziness. Remember how I was trying to source some andesite for a friend? The railroad ballast at the bottom of the hill may be miles and miles of andesite! The two top rocks are railroad ballast. The two rocks below are reference andesite pieces I brought along. While color isn’t always diagnostic, these rocks share texture and hardness and they don’t fizz. Yes, I carry a field bottle with acid. I’m not gettin fooled by limestone, thank you very much. I’ll be mailing off these suspect rocks to my friend.

I found two thin sheets of mica as well, sometimes called muscovite or potash mica. The latter name makes sense here since alunite is a potassium related mineral, hence, one might expect to find related minerals in the same location. Some mica sheets are so large and semi-transparent they were once used as window panes. Geology.com says, “The ability of muscovite to split into thin transparent sheets – sometimes up to several feet across – gave it an early use as window panes. In the 1700s it was mined for this use from pegmatites in the area around Moscow, Russia. These panes were called “muscovy glass” and that term is thought to have inspired the mineral name “muscovite.”

How would I proceed in looking for traces of gold? I stress traces, since this is only a curiosity hunt. Given the history of this hill and no production records, I can’t expect to find much if anything. I would, though, start at the bottom of the hill. See the railroad track? There are culverts to channel water underneath the tracks. If there are values on the hill I would expect to find some colors at these low points. Sample, sample, sample.

I’d also walk around quite a bit more looking for more quartz and simply looking. The more intensely you look at an area, the more you find. That sounds simple but it isn’t. People tend to walk away from ground way too quickly before really examining it.

Wendi at Minerals Unlimited (external link to my rockhounding site) says she has samples of alunite and that some weakly fluoresce. I’ve ordered a few and she’s putting a small box together for me which she will soon put into the mail. If alunite does fluoresce at all, that will greatly help with identifying it in the field. And I really have to have a reference sample in my hand to research any rock or mineral.
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