Gold Tellurides

[FiresEye]

So I've been reading a lot about tellurides and how they can contain up to 70% gold by weight, and that there's a specific process to remove the gold from them. While breaking some quartz ores down by hand, I've found some silvery metallic stuff which I think is Calaverite.. in quartz.... has anyone ever found any tellurides in the southeast USA? I live in North Georgia. I'm pretty sure that I have located a few telluride pockets, and havebeen doing a lot of picture looking and reading of what these rare minerals look like.

Also, for those of us who pan or sluice I have a question... Do you think the tellurides in the creek end up in the concentrates? I'd imagine they would. Also, if you crush rock and then pan, you have to be careful I think because the tellurides are much lighter than just placer gold. So moving on, here's some info I found on the web about tellurides...



It's long so scroll down and see what else is going on...



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This is only a primitive method of removing Gold out of Tellurides...
Basics; What you will need to do the job
1, 2 roasting pans [high temp] not aluminum foil type.
2, Standard table salt [equal amount to concentrate volume.
3, charcoal brickets.
4, outdoor area "well ventilated".

Step by step procedures...
1, classify your concentrates with a 20 mesh classifier...
2, mix the classified concentrates with equal amounts of salt...
3, put mix into a high temp roasting pan...
4. place pan with concentrates into a hot, well established coal bed...
5, leave in coal bed untill coals are completely consumed [overnite]...

What exactly is taking place...
Your concentrates have tellurides in them that according to our assay, are as much as 70% and as minimal as 30% in volume. You are heating the concentrates to an appx temp of 1000*F. What happens is that the salt and the heat enable the tellurides to burn off into a tellurium gas, leaving the chemically attached gold behind...

What will I see when done roasting...
1, actually nothing with the naked eye...
2, use at least a 10 power loop to get a view...
3, you are dealing with "micro gold" in very high concentrates...
4, if using a loop, you will see the remaning gold has kind of melted together into small globules...

Okay, now HOW DO I RECOVER IT...
1, get out your keene gravity bowl...
2, get it started up with a "GOOD SURFACTANT" in the water... [calgon]
3, NO soap w/lanolin or hand lotions in it...
4, remember you're dealing with ultra fine micro gold...
5, run your bowl with care and use caution, "don't get in a rush or get nuts"...
6, you will see GOLD in the gravity bowl, all will be in a 20 mesh and smaller...

What about the rest of the concentrates that I did not roast...
1, process them with your micro sluice or poop tube or gold wheel...
2, processing the remaining concentrates will get the free gold that did not pass thru the 20 mesh classifier...

Okay, I did all of this for what...
1, the Free Gold is running "according to assay" 1 troy ounce to each ton of classified concentrates...
2, the Gold Tellurides are yielding as much as 4-5 troy ounces per ton of classified concentrates...
3, how much is a ton of classified concentrates... [a 30 gallon garbage can in size]
4, or an average of 6-7, 5 gallon buckets of classified concentrates...

That's a hell of a lot of concentrates...
1, yup sure is, but so is 5-7 ounces of GOLD that you normally threw out...


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So guys and gals, this sounds like the sort of thing people talk about roasting black sand to fracture the gold out of them, maybe it serves a dual purpose to roast the tellurides as well... I'm going to do this on a camping trip, way out in the woods.. Because I imagine the fumes from this could get nasty... and I have a garden in my backyard so I don't want all those contams in the near area.


So here's what else I found out

"The chemistry of gold tellurides is relatively complex with a series of identifiable minerals. The more common gold-bearing tellurides are sylvanite ((Au, Ag)Te4), calaverite ((Au, Ag), Te2) and petzite ((Au, Ag3)Te2) with krennerite (Au4 Ag Te4) and montbroyite (Au2 Te3) less common. Gold tellurides occurrence is widespread and is often associated with some free gold and sulphide minerals. The density of gold tellurides (8.0 - 10.0) are lower than native gold and the colour are less distinctive shades of white, grey and black."

Yep.. based on That^^ description, I've for sure got tellurides showing in my ores... No gold visible, but micro gold in abundance not only through mica free gold but the tellurides..

Check it out yourself and discuss how many tellurides you think you have in your cons, if tellurides are common or rare in Georgia, and what area you live and what kind of tellurides you suspect you have found...

[Eu_citzen]

You should know that you can in 99.9% of all cases not ID a mineral by only looking at it..
You would need to do further testing of the minerals properties.

[FiresEye]

Yes I realize that it's hard to identify a mineral by its looks, but in this case, I have a pretty good idea of what it is. Also, I busted open 5 more softball sized quartz chunks today and one of them contained a chamber inside the rock of what appeared to be a telluride. Almost like a geode within the quartz, covered in this telluride lookin stuff.

I need to get some pics up, and will do so within the next few days, because I have other ores that I need looked at. This area I found the rocks at is within the gold belt of the southern Appalacian mountains, so there's a likely possibility.

Until then, here's something else I found out

[attach=http://www.eastpacsurf.com/images/calaverite%203.jpg]


This picture here is one off the web of Calaverite, a heavy gold telluride. As you can see, sometimes MICA can have this appearence, but simple tests will give an answer as to what it is.

[attach=http://www.dvminerals.com/img2006/S-351.jpg]

And here is a nother picture of a blacker looking telluride, which is one of the ones I identified today within my quartz ore.


Also, it is common knowledge that the old timers had very little info on tellurides, so a lot of them got tossed out, especially by the small timers... Just something to think about.

[FiresEye]

Now that I think about it, I'm really excited about all the tellurides I could and probably do have, not only in the rocks, but in my cons. I have to research though about which tellurides tend to end up in certain concentrates of what areas.

One important thing i've learned about gold in concentrates and ores is that a ton of it can be really really micro gold, so it's important to have a system to be able to mechanically catch these fines without mercury or leeching.

I like the clean gold system that uses magnets to use black sand as riffles, and in a system with a float trap that drives the surface under the surface to push anything floating down, on a slow moving table, with magnet riffles would work wonder to catch that micro.

Then, once you get your micro concentrates, simple get enough to make smelting worthwhile... maybe an ounce worth or so.

[LittleHarold]

I do find Calaverite in the Southeast. Museum Quality Specimens to be honest.

[Astrobouncer]

I have a report from the USGS around here somewhere (sorry I looked and I couldn't find it at this moment) but I do remember them listing some tellurides along the slate belt.

[mineron]

Interesting post. I have tried this a few times, but maybe I didn't let it roast long enough. Think I'll try a few more times as just seeing a few specks of gold come out of the rock would be worth the experience. Then when a better prospect is found I will be ready.