What were they looking for?

[geolover]

I could really use some help in identifying what other people were mining long ago. This mine runs through schist, it has a solid one foot thick stringer of red and white VUGGY quarts running through it. The stringer is like a big-fat plate (est 50'x100'x1') that sits about 20 degrees flat and into the hill. The quarts is crazy looking, it's white, red, and orange and very vuggy. I have sampled everything, especially the quartz and there are no signs of gold. I don't see any signs of gems. Maybe it was a mineral that they were chasing? A 100' tunnel is a lot of work for nothing?
I live near the Vail Lake area near Temecula, CA. There doesn't seem to be much gold activity around here. There's a couple of vertical shafts nearby. I found records for two prospect mines from the 70's , one for gold, other for feldspar? None of it makes any sense. All I can really count on is the schist and quartz.
Any recommendations on what I can look fo?? I added a few pics, hopefully they will make more sense of the geological setting. The pic of stringer is how it looks on the right hand side of shaft.

 

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[Lefty2u]

Is there a tailings pile? If so sample it. It could tell you what they
were mining. If there is not a tailings it means they took everything of
value and left the hole. If it is safe check the back and the face
of the mine to see if they left any different material for you to find.
Hope this helps
Lefty2u

 

[what]

Looks like a gold prospect to me...iron stained quartz and a decently mineralized zone. Could be that whoever was working it found a small zone that made sense to mine and chased the vein to a few spots looking for more rich zones in the area after that. Or I could be wrong of course but that seems to make the most sense for your area?

 

[geolover]

There is a tailings pile, last time I looked it seemed to be mostly schist. But you're right, I should really get in there and see what they left. If all schist, then they were after the quartz FOR SOME REASON? I'm mostly taking samples from the sides, the pic of the quartz on the wall represents what both sides of the tunnel look like. I'm pretty sure it runs out in the back, I'll have to clean it up to see. I will get into the pile to investigate, Thanks!

 

[geolover]

Looks like a gold prospect to me...iron stained quartz and a decently mineralized zone. Could be that whoever was working it found a small zone that made sense to mine and chased the vein to a few spots looking for more rich zones in the area after that. Or I could be wrong of course but that seems to make the most sense for your area?

That's what I was/am leaning toward. I'm taking samples of the quartz and everything around it. I figure that if I go into the sides pretty good that I should pick up a flake or two. I've found zero, and I really get into it, magnifying glass and all.
Imagine a plate lying flat on a table, you chew a path right down the middle of the plate because that's the only place gold was at. Just doesn't make sense, there's gotta be gold on the sides as well, at least a flake or two.
Maybe I stink at sampling, I break off chunks of quartz and schist that run along both sides of the wall, I even take good samples of the clay or weathered material that has precipitated down through the schist. The angle of the schist allows for a decent amount of moisture to make its way down, no drops, just weathered/soft. I mark my bags, go home, break and grind it up to about 20 mesh. Then I pan it all. Nothing! Not even a flake! Still though, I lean toward gold?
I'm not apposed to showing this spot to someone more knowledgeable. It's more about solving this geo question and having fun than any monetary value. I live about 3/4 mile from this spot, Take my Polaris down, grab samples, bring to my pump house to process.

 

[Jason in Enid]

Maybe the miner found gold in the quartz at the surface and thought it must contain more so he mined further and further in search of it until he finally gave up when he couldnt find more.

 

[Skunked68w]

How do you know your samples have no gold? Did you fire assay? No visible gold doesn’t mean no gold

 

[SaltwaterServr]

A flat, or nearly so, deposit is referred to as a tabular deposit or reef deposit depending on where you are in the world as far as the reader, not the miner. The terms are interchangeable.

Vuggy quartz that's iron stained? Gold and silver most likely, but you need to fire assay like Skunked68w mentioned. Visible gold is far and few between. I wouldn't guess how many thousands of modern miners never see visible gold in some of the largest mines in operation today, but they're cranking out 200K ounces a year.

100' isn't very big at all.

Think of it from this perspective. Some of the old miners found a small streak. They mined it because they found it. Not all mines were rich ones, some were just enough to make grub. It kept them in the game for another season where they either moved on to greener pastures or took up a different career. Most of us these days have the luxury of moving on from one property if we don't like the economics. That wasn't always the case, in fact, far from it.

 

[geolover]

How do you know your samples have no gold? Did you fire assay? No visible gold doesn’t mean no gold

I think you are correct, I broke up some of my best stuff tonight. I really really really inspected it, my best loop and lighting. I see nothing after four pans, then I see micro, micro, micro bits of goldish looking stuff rolling along with the water. These specs had separated from everything else and were just outside of a seam on the bottom of the pan. Whatever it is it is so fine that water just moves it around. Is it possible that it is so friggin' fine that water would move it around. I use the standard method of swirling the water in a circular motion to separate everything else from the gold. Is it even possible that the water is simply moving micro bits of gold around?

 

[geolover]

How do you know your samples have no gold? Did you fire assay? No visible gold doesn’t mean no gold

Can I do a fire assay myself?

 

[geolover]

A flat, or nearly so, deposit is referred to as a tabular deposit or reef deposit depending on where you are in the world as far as the reader, not the miner. The terms are interchangeable.

Vuggy quartz that's iron stained? Gold and silver most likely, but you need to fire assay like Skunked68w mentioned. Visible gold is far and few between. I wouldn't guess how many thousands of modern miners never see visible gold in some of the largest mines in operation today, but they're cranking out 200K ounces a year.

100' isn't very big at all.

Think of it from this perspective. Some of the old miners found a small streak. They mined it because they found it. Not all mines were rich ones, some were just enough to make grub. It kept them in the game for another season where they either moved on to greener pastures or took up a different career. Most of us these days have the luxury of moving on from one property if we don't like the economics. That wasn't always the case, in fact, far from it.

I think you're on to something, I'm going to research fire assays and check my materials out better. Thanks I really thought that I'd just see the gold with my loop after panning. If I see nothing, there must be nothing

 

[Twobrothers]

I think you are correct, I broke up some of my best stuff tonight. I really really really inspected it, my best loop and lighting. I see nothing after four pans, then I see micro, micro, micro bits of goldish looking stuff rolling along with the water. These specs had separated from everything else and were just outside of a seam on the bottom of the pan. Whatever it is it is so fine that water just moves it around. Is it possible that it is so friggin' fine that water would move it around. I use the standard method of swirling the water in a circular motion to separate everything else from the gold. Is it even possible that the water is simply moving micro bits of gold around?

Very Possible. Revealing video on some of the peculiar behaviors of fine gold (flotation) and an explanation of why tiny pieces of gold can move around so much. It all has to do with density vs size
https://m.youtube.com/watch?v=YniK_HzZxM
https://m.youtube.com/watch?v=YniK_HzZxM8

 

[Twobrothers]

Persistence and/or a lucky break

I hacked through/ open a lot of vuggy iron stained quartz until I found obvious visible gold for the first time. It helps if you know how gold comes in your district. Old mining reports sometimes make mention . I got a lucky break; broke open a slab of quartz. And there it was a shiny gold foil sandwiched in layered quartz. The first time I saw it I knew it right away. Once I saw that I knew exactly what to look for in the vein quartz. Each district (site, and even foot by foot on a vein at times) has its own geologic ore controls and peculiarities.

Basically it comes down to this:

-Either you find a report that tells you what you're looking for.
-You find a good crumb the old timers left behind and you know what to be on the lookout for
-You bang away at every piece of iron stained quartz (don't forget to check the contact zones with the hanging and foot walls) and examine everything closely until you find what you're looking for

Whatever it is have fun doing it!



PS thought I had while banging away at a quartz vein the other day. I wasn't finding what I was looking for that day. Namely gold and The geologic indications had my hopes up for a lot of it. God created the world at and for His pleasure. If it pleased Him to make a vuggy quartz vein without gold what can I say? If it's not there I could bang away at it all day? And find no pay. Maybe the old timers scooped up all the good stuff? Maybe they were just gold crazy enough to dig a 500ft trench through quartz and granite for nothing. Haul a gasoline powered air compressor 700ft. Up a 30% grade for the experience of it?

Anyway. Be safe. Whatever it is you get up to have fun. That makes the difference between living or just killing yourself slowly.

 

[Twobrothers]

Can I do a fire assay myself?

With some investment/ ingenuity and research you too can do a fire assay at home.
If you have a lot of money to blow that will help

In all serious I did it on the cheap and you can too.
This article will tell you everything you could possibly need for any fire assay.
https://www.911metallurgist.com/blog/fire-assay
https://www.911metallurgist.com/blog/fire-assay

For a quartz ore all you really need are Borax, Sodium Carbonate, Litharge, flour, and possibly some Potassium or Sodium Nitrate.

I've had success with a mixture of borax, Sodium Carbonate, litharge, a little flour and some Nitrate if its got a lot of undecomposed sulfides. Buy a decent 60 gram crucible Pack a piece of pipe with some Portland cement for cupels and there ya go. Build a forced air waste oil burner furnace(many different ways and YouTube videos to skin that cat). It's something fun to pour your own little miniature fusion smelt!

 

[geolover]

Thanks, I'll check out the vids. I've come to the conclusion that this is what I need to do.

 

[geolover]

I hacked through/ open a lot of vuggy iron stained quartz until I found obvious visible gold for the first time. It helps if you know how gold comes in your district. Old mining reports sometimes make mention . I got a lucky break; broke open a slab of quartz. And there it was a shiny gold foil sandwiched in layered quartz. The first time I saw it I knew it right away. Once I saw that I knew exactly what to look for in the vein quartz. Each district (site, and even foot by foot on a vein at times) has its own geologic ore controls and peculiarities.

Basically it comes down to this:

-Either you find a report that tells you what you're looking for.
-You find a good crumb the old timers left behind and you know what to be on the lookout for
-You bang away at every piece of iron stained quartz (don't forget to check the contact zones with the hanging and foot walls) and examine everything closely until you find what you're looking for

Whatever it is have fun doing it!
View attachment 1535746
View attachment 1535747

PS thought I had while banging away at a quartz vein the other day. I wasn't finding what I was looking for that day. Namely gold and The geologic indications had my hopes up for a lot of it. God created the world at and for His pleasure. If it pleased Him to make a vuggy quartz vein without gold what can I say? If it's not there I could bang away at it all day? And find no pay. Maybe the old timers scooped up all the good stuff? Maybe they were just gold crazy enough to dig a 500ft trench through quartz and granite for nothing. Haul a gasoline powered air compressor 700ft. Up a 30% grade for the experience of it?

Anyway. Be safe. Whatever it is you get up to have fun. That makes the difference between living or just killing yourself slowly.

I looked online for past claims or prospects, all I found were Two, one for gold, one for feldspar? I checked those places out, they were shafts that went down about 20-30'. They too, were in schist. I sampled those as well=nothing found. Obviously now I need to rethink my sampling processes and look for super fine micro gold. But in general, this area is not known as a gold bearing area. I have a feeler out to someone who is supposed to know this area, but has moved. Still going to pursue that. This stuff looks so good, so different from the norm.
I've got to figure it out. I checked out my own twenty acres a couple of years ago, probably have to redo all of that. Thanks

 

[Eu_citzen]

Can I do a fire assay myself?

You can, for sure. There are some things to consider:

1. Health & law issues - beware of the lead, acids and the waste you need to get rid of! (i.e. lead-contaminated cupels)

2. Is it worth it?
Doing an assay on your own takes a good bit of time and you need to keep tight quality control. (running double assays, making sure of no contamination etc)
You also need to learn to properly make up flux-recipes, interpret the ore - but these can be gotten by reading and experimenting.

If you don't have a lot of spare time, this might not be worth it.
A smelt will in my electric furnace runs until it doesn't react anymore - typically around 30-40 min.

 

[geolover]

With some investment/ ingenuity and research you too can do a fire assay at home.
If you have a lot of money to blow that will help

In all serious I did it on the cheap and you can too.
This article will tell you everything you could possibly need for any fire assay.
https://www.911metallurgist.com/blog/fire-assay
https://www.911metallurgist.com/blog/fire-assay

For a quartz ore all you really need are Borax, Sodium Carbonate, Litharge, flour, and possibly some Potassium or Sodium Nitrate.

I've had success with a mixture of borax, Sodium Carbonate, litharge, a little flour and some Nitrate if its got a lot of undecomposed sulfides. Buy a decent 60 gram crucible Pack a piece of pipe with some Portland cement for cupels and there ya go. Build a forced air waste oil burner furnace(many different ways and YouTube videos to skin that cat). It's something fun to pour your own little miniature fusion smelt!

View attachment 1535752
View attachment 1535753
View attachment 1535754
View attachment 1535755
View attachment 1535756

I took your advice. I was and still am working on getting all of the supplies to do my own assay. In the mean time, I sent a sample out to a lab in Arkansas, it was only $40. Good news! There is gold, just not a lot of it. I get the report and actual numbers in the mail in a few days, but it's low. He said that it was supper fine, that's why I couldn't see it.

Here's the thing, my sample was bits and pieces of everything around the vein and the actual vein of quartz. He crushed it all up and tested 60 grams, I think. I figure that the number (wt./ton) will go up if I can narrow it down. For instance, if is running in the quartz, and that's all I tested, the wt./ton would be higher. Maybe worth getting into. It's so close to my house that I could do it just for fun.

I'm just happy to hear that there is some gold, I guess I finally discovered what they were looking for. Now it's all about narrowing it down.

 

[geolover]

Congratulations to myself, this is actually the first time that I can say that I found gold! Technically I'd found it before, but since I couldn't see it, I threw it out. I'm going to get the assay numbers today, I already know it's super low. Then I'm going to sample all of the areas that I took my sample(s) from, extract the micro particles of gold using mercury. Once I narrow it down to the main source/area, then I'll send out a better, more condensed sample for assay. I really think the numbers will go up significantly.
I found gold!

 

[Twobrothers]

Congratulations to myself, this is actually the first time that I can say that I found gold! Technically I'd found it before, but since I couldn't see it, I threw it out. I'm going to get the assay numbers today, I already know it's super low. Then I'm going to sample all of the areas that I took my sample(s) from, extract the micro particles of gold using mercury. Once I narrow it down to the main source/area, then I'll send out a better, more condensed sample for assay. I really think the numbers will go up significantly.
I found gold!

Cool! Now it gets a LOT harder from here. If you're trying to make it pay. Got to find the hot spots on the vein. Close visual inspection foot by foot with a loupe or a little assistance from a good pinpointer like a Falcon MD-20 may be helpful. If you're deep in an unoxidized portion of quartz vein the gold can be practically invisible. It may show when the material is oxidized. I've seen it where a chunk of quartz pulled fresh out the face of a 40ft. adit looks bleach white and after five weeks on the dump it starts to weep yellows reds and copper greens out of its cracks. Bust it open and fleck of visible gold show. Visible gold is easier and more likely to show in the oxidized portions. In my experience the gold "shoots" or travels in vertical streaks. Sometimes in the vein of quartz. Sometimes on the contact with the foot wall, sometimes with the hanging wall. Think of it this way; silica and mineral rich high pressure high temperature hydrothermal fluid came jetting up deep out of the earth like a fountain quickly filling and solidifying in any void it can fill. The lighter more abundant mineral solutions (silicon, iron, sulfur) went rushing up with all their might seeking pressure equilibrium. The rarer heavier mineral solutions (containing gold, silver, lead, and copper) got dragged up along with the more abundant solutions along narrower openings; areas of higher pressure that had enough pressure differential to draw up the heavier mineral solutions from the deep. It's those variables, pressure, temperature, host rock, and event formation timeframe that contribute to different forms of fissure filled quartz mineralization.

The practical end of all that being you're not always necessarily looking for the fattest portion of the vein. Certianly sample and inspect because there are always exceptions. Likelihood is on a single contiguous outcropping of vein quartz from the same event formation the thinner portions of the vein rushed out under higher pressures and have a higher likelihood of heavy metal minerialization. Find your hot spot along the strike of the vein. Then follow that dip; the angle from which the vein protrudes from the earth (perpendicular or straight up and down would be a 90 degree- (vertical) dip); follow the paystreak down along the dip however it folds, faults, plunges or twists.

Ive done the whole thing with Mercury, it works but be careful. Not really an economically viable method for most people these days. And when you consider the recovery rates, potential health and environmental impacts it might not be worth it for your deposit. I'd say it's worth trying small scale for the experience if you're super careful. Nothing like your own gold out of a rock.

Here's a little I wrote on another post about my experiences using mercury. Best of luck.

http://www.treasurenet.com/forums/gold-prospecting/566621-ultra-fine-gold-dust-2.html

I've got a little experience with gold recovery using Mercury. Mercury can be made to work if your particles are a large enough size. Too small and it isn't very effective.

Mercury. Crazy liquid metal. Barely denser than gold. Know for its unique property to "surface tension-up" (amalgamate) gold.
Mercury effectiveness for Gold recovery is all about gold particle size and liberation from foreign (gangue) materials. So how does mercury work? Its all about surface tension. Mercury and native gold because of something to do with the electrons in their outer shells combined with their similar densities, and surface tension, mercury draws gold particles up in to its surface tension and dissolves a very small percentage (less than 0.1 percent of the gold by weight) into the mercury. There's basically no gold particle too large to amalgamate as long as you have enough mercury. However too small of a particle size and you can't get the interface of the respective gold-mercury surfaces. Not enough of the gold can come into contact with the mercury to break the mercury surface tension for it to draw the gold up. For the same surface tension reasons the gold must be totally freed from foreign materials/ coatings (gangue rock, oils, mineral coatings). Around 200 mesh and smaller is where mercury stops being as effective at capturing gold assuming the gold is clean, bright and shiny, which is usually a given for placer gold, not always the case with hard rock ores.
Heres some reference material to contemplate:
https://www.scribd.com/doc/43820757/...covery-Methods (Page 5).

For all its bad rap metallic mercury is pretty safe to living organisms. Vaporous mercury and mercury ions, salts and organic compounds are the big ouch. You could take a swig of metallic mercury (which they used to prescribe for constipation) and it would run through you along with everything else for an interesting bowel movement.
So metallic mercury okay, vaporous mercury, mercury ions, salts and organic compounds whew boy! There've been instances where a couple drops of organic compound mercury killed people. So how do you keep it metallic state? Basically use as little as possible with chemically non reactive materials. Concentrated washed placer sands? Pretty safe. Raw hard-rock ores? Boy you better watch out. All the sulfur and who knows what else in raw hard rock ores can compound with mercury and form who knows what manner of biologically soluble compounds.

Some notes on my experience with fine gold formation/ ore genesis. I did some experimenting with recovering gold from pyritic origin hard rock ores. During the formation event the gold is deposited along with pyritic (sulfide) minerals. Predominantly within iron pyrites in my district, although know to form in calcopyrites and aresno-pyrites (You really don't want to mess with arseno-pyrite). The gold is contained as fine particles and coatings within the crystaline matricies of the vaious pyrite (sulfide) minerals, and is liberated as finely grained sheets, layers, and pockets of finely aggregated gold particles when the pyrites oxidize away. The material I experimented on had gold generally 300 mesh and smaller, a dust more or less. They occur in concentrations enough to be visible when aggregated together but they are not a singular agglomerated consolidated mass of gold but rather aggregated particles of fine gold.
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Gravity separation: Basic gravity separation by panning samples was not effective for me. Probably for two reasons 1) achieving a fine enough particle grind/ liberation size and 2) primitive method used (panning). Probably would help if I ground and classified to a finer size before attempting.

Amalgamation: I achieved a result but low recovery yield when I attempted amalgamation. Process: ground rich samples to about 16 mesh and roasted to neutralize as much reactivity with the mercury as possible. Ran the material in a homemade pan mill. Ran with mercury in the bottom and wetted to the consistency of a thick milkshake with a little jet dry. Grind time 1 hour 3-4 tuna cans of material at a time. Ground to a fine mud and floated out the grind with water. Observed pieces of mosquito eye gold flow out un-amalgamated in the tailings. Recovered mercury and retorted and got a little bead of gold. But I suspect I lost a lot of it, although I do not have assay results on the feed stock and tailings to compare. Click image for larger version.

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Some kind of chemical leach may be most effective but I cant make any reccomendations there as I've not sucessfully executed a process I am comfortable with yet.