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Another silver specimen


Sonoran Dave

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Beeped a little wash yesterday and it produced an interesting little specimen. It's about the size of my thumbnail and 9.1 dwt. When I first dug it up, I assumed it was old chunk of lead and just pocketed it. 

On the way down the mountain I stopped to rest and washed it off with some spit and water from my bottle. I could see a little showing of gold in various places around the heavy rock. When I got it home I carefully cracked the end of it off and was both disappointed and happy to find it slam full of silver too. The pictures don't show it very well, but it is quite striking. 

The good part is this was found within 100yards or so of the head of the wash. A pretty small area to hunt up any siblings...or even a pocket. :fl:

 

 

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Swim out there and get the rest :)
Nice find bud.

Tom H.

 

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Is that native silver or a silver ore specimen? Hard to tell from the photos. Did you do a streak test on it? Interesting find in any case.

Edited by Morlock
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Maybe 70% free silver in a blueish quartz matrix. Streak was silver and nitric acid confirmed my assumption. 

The majority of the ores in this area are polymetallic. Any showing of visible free gold is pretty decent grade ore, to have this much silver in it is icing on the cake. :D

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To test for silver, you put nitric acid on it and it bubbles?  Will the ore bubble also, or just the native silver.

 

I'm trying to get past the gold.  Lately I've convinced myself I've tossed out tons of silver ore.  I really doubt the Spanish were out here to hunt for gold only.  They must of found plenty of silver.

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I'm watching this.  It's pretty interesting.  It's on smelting silver.  First, he crushes it, gets a concentrate off a miller table, roasts the Sulphur out, and then smelts the ore.  About 50% silver from the concentrate.

 

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33 minutes ago, Swampstomper Al said:

I meant to ask you about that little speci you eyeballed & crushed a few days ago if that was Ag along with the Au..?
I'm assuming it is.. How much distance between the two finds, Dave..?

Swamp

No noticeable silver in that other specimen. Several miles separate the two locations. 

I posted it on facebook on I got a reply from Chris Ralph that it looked to him like a silver - lead mixture. Waiting to get more info. 

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36 minutes ago, ArcticDave said:

I posted it on facebook on I got a reply from Chris Ralph that it looked to him like a silver - lead mixture. Waiting to get more info. 

It does look like some massive galena which I found near the Black Rock Mine outside of Yuma in Arizona. Looked up the assay reports on that mine and it had very high silver content. Up to 2200 ounces ag per ton. But very hard to tell just by looking at the photos exactly what you have without further testing.

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6 hours ago, ArcticDave said:

When I applied it to the small piece I broke off it bubbled very noticeably but only on the silver spots. The quartzy stuff didn't react in the few seconds it was exposed to it. 

 

As a total newbie with the use of nitric acid, anything I find on the net about it is for testing jewelry.  I wonder if it would react with the other stuff in the rocks.

I looked a little more at the Nitric Acid, and I will stick to the silver test kits off of E-Bay and Amazon for around $7 or less.  Those look like 1 ounce bottles, so should have at least 400 drops per bottle.  I looked at Nitric Acid off of Grainger, and a half liter bottle of 50% is $49.  I know it's lab grade, but there's not enough out there to tell me if I can use it test silver.  I would at least get to know how to use it off the Amazon kit, and if it works out, it's still cheap enough to get off of Amazon for a replacement.

Anyone recommend any books on this?  I've reached the end of the internet on field testing for silver in ore samples.  There's one books on Amazon "Field testing gold and silver" by William Merrit.  I wouldn't mind getting one, I just don't know if it's any good.  It has Amzon look inside, but only shows the title page and a couple of other pages with no info.

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Here is a picture of a pure silver specimen both before I scratched it and after. This came from the Serrita Mountains south of Tucson. It was a tiny signal until I kicked the rock over to get the zip zip. I looked at it thinking that maybe someone shot a rock with a gun? after i picked it up I stuck my finger in it it was soft enough to scratch with my nail.

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Heard a little more from Mr. Ralph, he thinks it's Lead-silver ore of some variety. Only way to know for sure would be to find more of it and have an assay done on it to determine % of each. 

Since a tiny stringer of lead ore, even if very high in silver, wouldn't be much of a prize, I'll just put this specimen on the interesting rocks shelf and call it good. 

Chris did say that lead will react with nitric too. I tried a drop on a large lead button I have. It only reacted in a minor fashion, unlike the reaction I get from the specimen. So I think this specimen has a much higher silver content. 

On the subject of galena...I've seen local galena, and it doesn't look like this. This is very bright and completely lacks the dark coloring I've noticed on galena in the past. This could be due to higher silver percentage....as Morlock stated there are some very rich galena deposits out there. 

Interesting find nonetheless :200:

Chrisski: I don't know squat about silver. Finding that native silver nugget a couple of months ago was my first exposure to it. Maybe someone else has a good answer for you. 

Fishing: Interesting find. Is that piece big enough for a streak test? 

Silver streak is silver

Lead streak is silvery too but more gray colored. 

A hardness test would add clues as well. Lead is very soft, silver is quite a bit harder. 

Edited by ArcticDave
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1 hour ago, ArcticDave said:

 

Chrisski: I don't know squat about silver. Finding that native silver nugget a couple of months ago was my first exposure to it. Maybe someone else has a good answer for you. 

 

I certainly don't know anything of lode mining or prospecting for other than gold.  Plenty of info on placer mining, but as far as lode mining, boom, you've reached the end of the internet.  I don't think anyone is hiding information, I just think there's so few lode miners or silver miners out there doing it, there's not much info available. I also think I've walked by plenty of silver ore without knowing it.

 

Silver is also not that valuable when you see the work you need to put into it.  With gold at 1160 an ounce and silver at 16 an ounce, I'd consider going hard rock into a vein that had a couple of ounces per ton in gold, but with silver 1.5% the price of gold, I'd need pounds per ton of silver to make it work my effort.  The types of diggings I'm talking about are like the small trenches you see dug throughout the area.  Those look like a lot of work, and I'm willing to do it, but I'd like to get a bit more than minimum wage once its said and done. 2 ounces a ton is a lot, and all these trenches and prospects people started were stopped for a reason, and not because they were making money hand over fist.

 

I've got a vein of something on my claim that someone spent a lot of time going after.  Don't know what it is, but because of the dark color, I'd like to think silver.  The geological maps show it as a place not likely to find gold, because it is basalt lava flow, and I've never found placer in that part of the claim, but someone spent days or weeks digging some prospects to go after something in the vein.  I've got samples to be sent off for assays, but will be a while before I send those off.  I can see myself filling 36 buckets (1 ton) of ore and crushing it to get a couple ounces of gold if and only it can be free milled, but if it was silver, it'd take pounds for me to break even.  With this ore, I feel I could get a few tons before the vein played out or I had to dig a shaft, and I have no desire for that.

 

Other than gold or silver, I don't think there's anything that has been mined locally that could be worth my while.  Titanium, copper, manganese, and other metals are not for the small time miner, that's for open pit.  For Lead and a couple of other metals, the ore is not even processed in the US anymore.

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Don't let that basalt fool you. Depending on location, epithermal deposits can be formed in tertiary volcanic rock. 

I'm with you on the rest of it. With no means of processing the ore...it's not worth hauling off the mountain. 

Those shallow cuts are possibly old pockets that were worked out. Seems to be a common theme with epithermal stuff. Free gold was present in the top layer, but not further down. How far down depends on a lot of things, like how much pyrite was in the ore, how much water and oxygen were around to leach the pyrites...etc etc. 

I would work a vein if it averaged 1oz/ton AU. That can be profitable for a small miner if it's free milling. It doesn't take long to gather up a ton. :Diggin_a_hole:

 

 

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Unless you have native silver, it probably wouldn't be worth processing on a small scale since it would likely be tied up in sulphides in which case roasting would be required. Just wouldn't be worth it IMHO.

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13 hours ago, fishing8046 said:

Here is a picture of a pure silver specimen both before I scratched it and after. This came from the Serrita Mountains south of Tucson. It was a tiny signal until I kicked the rock over to get the zip zip. I looked at it thinking that maybe someone shot a rock with a gun? after i picked it up I stuck my finger in it it was soft enough to scratch with my nail.

 

 

Native silver tarnishes, and i dont think it will dent with a fingernail.....That mineral could be molybdenite

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Adam--Thanks.

 

I do know that molybdenum was mined in Central AZ during the war.  I looked up molybdenite and I'm pretty sure I've seen a bit of that, especially when I take out my loop.  These are pics from British Columbia, but look very close to what I see quite a bit of.  I often see it in the red to black quartz that should be good for gold, which is close to what the picture is.

 

It's worth about $6 per pound, but that is probably processed.

 

 

 

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So I didn't know this thread was here until now. On Facebook I was seeing Dave's specimen on my phone - and the picture is much better here on my laptop - I can see the cubic cleavage of the mineral now - its galena. Galena is lead sulfide, mostly lead by weight - about 86 or 87 % lead. It doesn't normally sound off on a PI, but it can. It sounds off easily on a vlf. 

Normally a typical silver lead ore will run in the range of 1 to 3 ounces of silver per percent of lead - that means 1 to 3 ounces of silver for every 20 pounds of lead. So an ore with 10% lead might have 30 or so ounces of silver per ton. The silver is in the galena with the lead.

Now I watched that video - and the guy does not understand the chemistry. The button he gets is mostly lead. It will have probably something like 1 to 3 ounces of silver for every 20 pounds. Since it looks like his button has maybe two ounces of lead, he probably doesn't have even a gram of silver alloyed in with the lead. There is another step that he didn't do to separate the lead from the silver. That step is what is done commercially to produce a fairly pure silver product.

I have a bigger furnace and bigger crucibles and about 10 pounds of Galena . One of these days I am going smelt it all in several steps in order to do a video and an article for the ICMJ and explain the whole thing and how it works and how you could do back yard smelting all the way from raw ore down to a silver bar. I will separate out any gold too and probably get a little button of that as well. 

Edited by Reno Chris
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