Well, damn. There is gold in that stream after all! Thinking of a plan.

Boarteats

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So, funny thing happened to me this weekend. Collected some magnetite from a backyard stream for my first go at smelting iron. (Just built my first forced air propane crucible furnace.) Used a magnate to pull the magnetite from the stream bed clay.

There I was Saturday grinding up a couple of handfuls of material via mortar and pestle when I look down. What do I see? About a quarter inch piece of gold flattened against the bottom of the mortar. The gold must have been encased in one of the bigger magnetite chunks. This was a bit of a shocker! I'd panned that stream several times in the past looking for gold but only came away with bits of pyrite and flakes of mica. Moreover, the damn stream is in my back yard. Go figure...

A closer look at my magnetite (after a quick dry panning) revealed a good number of small bits of gold (needed loop to see them). So question is, why did I completely miss seeing any gold in the past? Part of the answer is that I never bothered looking closely at the black sands, iron oxides, and the such. But, shouldn't I have still seen at least a little gold. Perhaps my panning skills need some work. Might the gold only be stuck in with the magnetite and no where else?

Couple things occur to me for next steps.

1. Find a reputable assay company and send off some samples to them as a sanity check. Can anyone make a recommendation?

2. Learn how to smelt gold that is mixed in with iron oxides. My first attempt yesterday didn't go very well. Lol. Ended up with a bunch of pretty black glass with little bits of iron, gold, and graphite (from my crucible, I think) all mixed together in an unholy mess. I'm reading up an Chapman flux and cuppellation (sp?) now. Should have probably done this first. Seems like a messy bit of business. Not thrilled with the idea of using lead.

Read up a little on the AR approach. Oh, hell no! As it, the wife is not thrilled with having 3000 degree blast furnace in the back yard. Adding caustic acids and other chemicals into the mix is not a good recipe for wedded bliss.

Quite an adventure so far. Any thoughts from all you seasoned, professional gold prospectors out there?
 

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Duckwalk

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Missing it to begin with could have had a number of variables. Id say the first one was classification. If you are just panning, classifying can prove to be one of the most useful steps in fine gold recovery. Its possible the gold didnt sink to the bottom of the pan if the rest of the pan was filled with matierial too big and blocked it on the way down thus washing it out of the pan. As for smelting, a number of fluxes can be used, good ole Borax works well as a flux in blacksmithing i know. I hear sand is actually a decent flux as it floats on top and any impurities get trapped within. If the gold is mixed in with the black glass you have, sounds like the gold didnt get to melting temps and just sat solid inside the molten glass and not falling down into a "button" as it should have.
 

vpnavy

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I noticed this was your very first post - so, Welcome Aboard BoarTeats! You didn't list your state (or country) in your profile. So, you might consider jumping over to Sub-Forums: Select Your Area.... and selecting location information (i.e., clubs, hunts, finds, legends, maps, etc.) directly related to your state (or country).
 

winners58

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under some circumstance especially along coastal areas gold can get encrusted into the black sands.
the oldtimers would run their heavies through a portable stamp mill to get better recovery rates.
as far as making iron from raw black sands I think they use limestone as a flux on an open hearth
and pound the impurity's out. might try your hand at Fire Assaying https://www.911metallurgist.com/blog/fire-assay
 

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arizau

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So, funny thing happened to me this weekend. Collected some magnetite from a backyard stream for my first go at smelting iron. (Just built my first forced air propane crucible furnace.) Used a magnate to pull the magnetite from the stream bed clay.

There I was Saturday grinding up a couple of handfuls of material via mortar and pestle when I look down. What do I see? About a quarter inch piece of gold flattened against the bottom of the mortar. The gold must have been encased in one of the bigger magnetite chunks. This was a bit of a shocker! I'd panned that stream several times in the past looking for gold but only came away with bits of pyrite and flakes of mica. Moreover, the damn stream is in my back yard. Go figure...

A closer look at my magnetite (after a quick dry panning) revealed a good number of small bits of gold (needed loop to see them). So question is, why did I completely miss seeing any gold in the past? Part of the answer is that I never bothered looking closely at the black sands, iron oxides, and the such. But, shouldn't I have still seen at least a little gold. Perhaps my panning skills need some work. Might the gold only be stuck in with the magnetite and no where else?

Couple things occur to me for next steps.

1. Find a reputable assay company and send off some samples to them as a sanity check. Can anyone make a recommendation?

2. Learn how to smelt gold that is mixed in with iron oxides. My first attempt yesterday didn't go very well. Lol. Ended up with a bunch of pretty black glass with little bits of iron, gold, and graphite (from my crucible, I think) all mixed together in an unholy mess. I'm reading up an Chapman flux and cuppellation (sp?) now. Should have probably done this first. Seems like a messy bit of business. Not thrilled with the idea of using lead.

Read up a little on the AR approach. Oh, hell no! As it, the wife is not thrilled with having 3000 degree blast furnace in the back yard. Adding caustic acids and other chemicals into the mix is not a good recipe for wedded bliss.

Quite an adventure so far. Any thoughts from all you seasoned, professional gold prospectors out there?

Duckwalk gave one of the most likely answers as to why you did not see the gold before if there was any to see in the first place. Classifying eg. sieving the material (actually the concentrated material obtained from panning off most of the waste material) to like sizes prior to panning. When gold is mixed with black sand of the same size it is at least 3 times as heavy and is pretty easy to separate when panning. If gold is much smaller than the other material it is much harder to separate it if at all. If you are really interested then you should get a set of classifying screens ranging from about 1/8" down to 60 or 100 mesh or smaller. Here is one set available on Amazon and there are others available elsewhere https://www.amazon.com/Camel-Mining-1V_CM-026-Nesting-Classifier/dp/B009WV1QW4. It is also possible that gold was coated with some black mineral compound as seen here and was missed in your initial efforts of panning your creek. http://www.treasurenet.com/forums/g...large-black-gold-nugget-found-do-i-clean.html.

Have fun and welcome to the forum.
 

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goldenmojo

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We get small sulphides and cubes of dark material frequently where we mine that have small specs of gold in the outer layer of the cubes. On some the gold is large enough that it is visible with the cubes in the pan. Othertimes we check some of the cubes with a loop and spot the color that way. I don't personally spend any time trying to process them.
 

Bejay

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In Oregon, the black sand formations in and around the ocean beaches have tannin oils infiltrated into the deposits: coating the very fine gold with basically vegetable oil. The old timers would boil the black sands in lye water to remove the oils; and thus the gold could be separated without the use of mercury. Whiskey Run on the central Oregon beach was well know for kettles "a cooking" but they were for both the "gold/lye" and "shine". Much of the black sand deposit layer still exists today at "Whiskey Run" but it is part of the State Park System now.

Bejay
 

wildminer

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Thanks for that scoop Bejay. I live near WR and did not know about the kettles and that process for that matter. Very interesting.
 

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Boarteats

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Appreciate the input Duckwalk. I can definitely see how classification could have been a problem based on your insight.

Temperature-wise, I reached gold temp melting range and then went on to over achieve on this front. Melt was completely liquid and vigorously boiling by the time I pulled the crucible from the furnace. Had to have been up near 3000F. ...not that this is necessarily a good thing based on some recent reading. I used fire brick rated for up to 2750F to create a makeshift form. The melt was hot enough to melt a couple/few mm of the fire brick. Thinking that I could dial this back a bit.

I think the flux was a big problem. Perhaps I should have added silica and something like manganese dioxide to deal with the iron oxides. Still reading up on the science of gold smelting flux.

Winners58, arizau, Goldenmojo, Bejay, vpnavy appreciate the comments and recommendations.
 

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KevinInColorado

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Boarteats

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Kevin, appreciate the info. No, I didn't realize that I could vaporize gold! Yikes. Definitely, will dial back the temp.

I carried out my first smelt using Chapman flux this afternoon. Was an improvement, but was too viscous. Melt was complete but only half poured out of crucible. Had a couple small (largest was 1/8 in) blobs of silvery, soft metal in the half that poured out. I would have liked to have all the resultant metal together in one blob. Also, seems to me that the metal should have fallen to the bottom of the molten slag before everything solidified. No way to know how much else I've missed. However, I'm happy to see some type of interesting result! Going in the right direction. Woot!

What ratio of borax, silica, material do you use?
 

KevinInColorado

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If too viscous then add more borax. If too dark, add more silica.
 

mendoAu

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Ya kinda answered your own question why ya missed it. Two things stick out when I watch some of our friends that come here and try their gold getting skills. You can really blow your gameplan if you have pre-determined that there is no gold. And number two...and this is kinda standard, people take forever to pan a half shovelfull of material...hoping not to miss a speck. More than often ya hear "is that a speck...?". If you can't tell then wash it back into the creek, it will be there next time. I've just lately had a couple of new friends come up a few times. They got a good positive attitude and the last couple of times I've noticed that (hum, wonder who said what...HA!) they will dig a dozen quick places, pan as fast as they can, ponder the outcome of those pans and decide where to set up the power sluice. I haven't told them yet that cause I suggested to pan in the same spot always right above that nice piece of polished bedrock sitting a foot under water that some day we'll use that nozzle and suck up that spot and retrieve anything lost out of a pan in probably less that an half-hour.
PAN MORE - WORRY LESS
 

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Boarteats

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... And number two...and this is kinda standard, people take forever to pan a half shovelfull of material...hoping not to miss a speck. More than often ya hear "is that a speck...?". If you can't tell then wash it back into the creek, it will be there next time.
PAN MORE - WORRY LESS

Thanks mendoAu. I'm starting to appreciate this sentiment more and more as read up on and watch YouTube vids about gold prospecting. Finding one fleck of gold is fun but not profitable. Finding a lot of gold flecks is both fun AND profitable!

This has me thinking about ways to collect and process this material at greater volume and in far less time. A big challenge for me is that all the heavies in my stream are covered in black, magnetite like material. This is similar to the video the @arizau posted earlier in this thread. I've been finding small bits of gold when crushing the heavies in a mortar/pestle. Most of the little black stones crush into powder. A few just flatten out when hit. This is where the gold seems to be. Moreover, I'm not sure why yet, but some of the malleable bits of metal I find this way are attracted to a neodymium magnet. Smelting the heavies after crushing to less than 100 mesh and removing magnetic bits has so far ylelded small amounts of a soft silver/grey soft metal. Having said this, an analysis of slag after melt showed diffuse but identifiable gold. Not a large amount but not insignificant given original volume of material processed. Interesting puzzle. Will take more experimentation to understand what I'm seeing and to know if this is worth pursuing in the longer term.

I attached a pic of the silver/grey smelted material. Not sure what it is yet.
 

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Eu_citzen

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The silvery/grey material has a sulphide look to it. Possibly galena?

Either way, if the slag is thick, more borax helps. I like to add some saltpeter to, as I feel it sometimes helps with viscosity.
A good temperature seems to be around 1000* C.

You can replace lead as a collector metal in assaying with bismuth oxide. But it's a tad more expensive...

As a side note: Cool another iron smelter! I plan to get back to smelting iron this year. Been learning blacksmithing for a year now first.
 

Skunked68w

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Have you tried to process your black sands in a rod mill? If you are seeing visible gold at the bottom of your mortar after grinding, seems like your black sand is perfect for a rod mill
 

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Boarteats

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Have you tried to process your black sands in a rod mill? If you are seeing visible gold at the bottom of your mortar after grinding, seems like your black sand is perfect for a rod mill

Hadn’t heard of a rod mill before now. Did a quick search. Looks really interesting! I’ll look for diy design. Will probably try it out. Thanks!
 

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mendoAu

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Milling ore is not my forte ( I'm lost without some kinda suction nozzle ) but it sounds like in your part of the world with the gold bearing material you can get it seem's like that milling technique has been around for a looooog time so it must have some merit. Just did a educational google search and learned a thing or to. :

https://en.wikipedia.org/wiki/Arrastra
 

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Boarteats

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Iron + ?

I've read that a SMALL amount of iron can be in close contact with precious metals like platinum in nature. However, I've not seen information discussing precious metals on, covering, or alloy-ed with iron in nature. Of course, I'm new to gold prospecting. ...Anyway, the reason for the comment is that I'm starting to find pieces of malleable metal such as those in the attached pic while crushing up pieces of magnetite. Some of these suckers are strongly attracted to a neodymium magnet, so guessing lots of iron there. However, the image suggests that gold, silver, and/or copper (other) might be present as well. If so, would such an occurrence be terribly uncommon?
 

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arizau

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I've read that a SMALL amount of iron can be in close contact with precious metals like platinum in nature. However, I've not seen information discussing precious metals on, covering, or alloy-ed with iron in nature. Of course, I'm new to gold prospecting. ...Anyway, the reason for the comment is that I'm starting to find pieces of malleable metal such as those in the attached pic while crushing up pieces of magnetite. Some of these suckers are strongly attracted to a neodymium magnet, so guessing lots of iron there. However, the image suggests that gold, silver, and/or copper (other) might be present as well. If so, would such an occurrence be terribly uncommon?

Google search "bog iron". That may account for some of what you are finding. In colonial days it was used to make iron and steel implements in your area. Other than a natural formation, they may be remnants from some crude processes by the blacksmiths or refiners of the day that were tied up in slag then eroded out and deposited by stream action.
 

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