Prospecting in shale-heavy areas

AuSomeness

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Hello all,

I have a question about prospecting in shale-heavy areas. Last year, I broke up some shale and panned out what I could find. The water turned a bit gray'ish, and I was concerned that there may be some heavy metals (i.e. mercury) or something else unknown in it. I did find some chunks of shiny material. It makes the 'ca-ting' sound like gold does in a vial. I'll post some pics of this shortly. My questions are:

(1) Are there any dangers prospecting in this type of material (shale or this type of rock, especially in California / the Sierra Nevada / Motherlode)
(2) What might one find in this material? I'm curious about the "metals" I have found, which are reddish in color.

I'll post pics as soon as I can.

Thanks!
 

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GoldpannerDave

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I hope you can post the picture soon. It is hard to tell otherwise. Sounds interesting, though.

Some shale locations in Colorado gave very good gold when the shale was basically perpendicular to the flow of the river. It trapped gold and was very rich in Breckenridge. It traps other things, too, but I cannot comment on what you might find in the Sierra Nevada, California area.
 

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AuSomeness

AuSomeness

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I've worked material like that and wondered the same thing... :dontknow: It igets very gray and odd. hope to see an answer.

Good to know I'm not alone on this! Okay.. let's see if I can get that photo...
 

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AuSomeness

AuSomeness

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Ok, take a look at these. The material in question is the reddish / shiny stuff. This is after the liquid has settled. I will post a pic of it cloudy as well.

ausomeness-shale-material-01.jpg

ausomeness-shale-material-02.jpg
 

et1955

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Shale its just sediments and clay hardened over time and pressure, up here in Washington State there are places where in-between the layers of slate wire gold is formed, more valuable that a nugget. I have found areas between the layers of shale that is so decomposed that when panned it turns the water in my pan into what looks like mercury, I have found a lot of my larger nuggets cleaning out these decomposed areas along the river.
 

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AuSomeness

AuSomeness

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Ed,

Thanks for the reply. Question: why is the wire gold more valuable? I assume it's because of the unique shape.

As for your comment about turning the water to what looks like mercury when panning shale material, this is exactly what I am experiencing. I found the stuff in the photos late last year. I had forgotten all about it until I found more material just like my original batch over the weekend. I panned some tonight and I got the same results: a strange, gray, muddy-looking color when put into water. I've attached a pic of what the water looks like when agitated.

AuSomeness-shale-material.jpg
 

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AuSomeness

AuSomeness

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Here are some decent pictures of the metalic pieces I found. They are fairly square / rectangular (in general). They appear to be not worn, which makes sense, as they were extracted from a host rock/material. There appears to be a variety of material in them or on them. There is black, red, gold, and what looks like mud-colored material present. What do you think?

AuSomeness-mystery-metal01.jpg

AuSomeness-mystery-metal02.jpg

AuSomeness-mystery-metal03.jpg
 

DDancer

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Pyrite crystals. :)
 

Hoser John

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There are many places in calif where the shale has great gold. Like pages in a book fulla gold.Especially the Merced...John
 

kayakpat

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Shale I believe is just ground down rocks and minerals in to very fine particles then compressed together, not sure,
 

et1955

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Check out " Liberty, Washington wire gold " on the net and YouTube. Potato size nuggets are found there plus crystalline wire gold. You are right, because of it's rarity and growth pattern it is highly prized for specimens and jewelry.
 

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AuSomeness

AuSomeness

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Pyrite crystals. :)

I'm not sure about that. I've seen lots of pyrite, but I've been wrong before. Probably the most difficult part for me is that these are not weathered by the environment. I will have to clean one up and test it for brittleness. If it is iron pyrite, from what I've read, I suppose arsenic could be a concern. FUN! lol
 

GoldpannerDave

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I'm not sure about that. I've seen lots of pyrite, but I've been wrong before. Probably the most difficult part for me is that these are not weathered by the environment. I will have to clean one up and test it for brittleness. If it is iron pyrite, from what I've read, I suppose arsenic could be a concern. FUN! lol

Arsenic in small quantities is not deadly. The LD50 is 15mg/kg; or if you weight about 200 lbs, the dosage is about 1.4 grams. That is an awful lot to get from working with a small crystal of your material. First, from the sizes in the pictures, it would have to be almost all arsenic and then you would have to eat it (since that is the oral or by mouth dosage). Absorbed through skin is even less toxic (higher LD50--but I cannot find the data).
 

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AuSomeness

AuSomeness

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Arsenic in small quantities is not deadly. The LD50 is 15mg/kg; or if you weight about 200 lbs, the dosage is about 1.4 grams. That is an awful lot to get from working with a small crystal of your material. First, from the sizes in the pictures, it would have to be almost all arsenic and then you would have to eat it (since that is the oral or by mouth dosage). Absorbed through skin is even less toxic (higher LD50--but I cannot find the data).

Thanks for the info, GoldpannerDave. I tend to play it safe.
 

kayakpat

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I would think the wire gold would be very rare, seems like it would have to be formed in soft rock that disagrades and or buried in soft material to protect it
 

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GoldpannerDave

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Thanks for the info, GoldpannerDave. I tend to play it safe.

Yes, better safe than sorry. Arsenic certainly can kill, but given all the parameters, I think it is a very small risk for your situation. A group back in Persia about a millennium ago used to eat arsenic to build up an immunity to it; that group has the name that came to be known as the Assassins. Rumor has it that the immunity to arsenic was then used as a tool in assassination. Sort of like "The man in black" and iocaine powder, I suppose.
 

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AuSomeness

AuSomeness

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There are many places in calif where the shale has great gold. Like pages in a book fulla gold.Especially the Merced...John

Near the Merced is where this material was found, John. I had to think about it, but this was during one of my first outings. If I remember correctly, I got the idea to look at this type of rock from EagleDown's thread. I'd love to find a "book" like that. I could read all day! :thumbsup:
 

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