Archaeologica.org

I'm a bit puzzled about the link on Zinc, Silver, Iron, Min. Silver is found as an ore in combination with these elements, it's called Sphalerite.
Zinc is widely used as a rust proofer, the process, over here, is called Galvanization

I'll be looking up Sphalerite immediately.

Hell, the stuff looks like pyrite. I'm gonna study it a bit more.

It's rather pretty stuff actually, depending on the mix of course.

You got me thinking, Digit...always dangerous.

I briefly wondered if Charlie had found a natural ore but it seems not to be the case.

http://www.galleries.com/minerals/sulfi ... haleri.htm

Seems to be more of a crystal though.

Galvanizing with zinc is done by electrolysis. I am not aware of any chemical processes that ancients could have utilized. If zinc and iron are melted, they may form an alloy but it will not be corrosion resistant. Chromium is used for that.

When I was a kid Min you could write to mining companies and they would send you an educational pack consisting of all sort of minerals, and the piece of sphalerite I received would appear to have been one small crystal like Charley's pic.

Galvanizing with zinc is done by electrolysis. I am not aware of any chemical processes that ancients could have utilized. If zinc and iron are melted, the may form an alloy but it will not be corrosion resistant. Chromium is used for that.

So you think the anaerobic enviroment scenario makes more sense, as far as the lack of rusting goes?

It is indeed Monk, I wasn't suggesting that plating was involved. Silver is found in combination with all sorts of other minerals. I don't know if it's found as native metal like gold though.
Pure Iron doesn't corrode very badly without help from Zinc or any other mineral, it's only when you alloy it with carbon thathe rot sets in.

Sphalerite

Sphalerite can be difficult to identify because of its variable luster, color, abundant but obscured cleavage and crystal habits. So difficult was sphalerite for miners to distinguish from more valuable minerals such as galena, acanthite and tetrahedrite, that they named it sphalerite which is Greek for treacherous rock and blende is German for blind or deceiving.

All the mentioned minerals above are sulphides, as is pyrite, which I thought I was dealing with exclusively.

Charlie Hatchett wrote:So you think the anaerobic enviroment scenario makes more sense, as far as the lack of rusting goes?

For me it depends on the ratios of the metals. Do you have an ore of iron, an ore of silver, or zinc the principle metal? Zinc will oxidize white, silver oxidizes and turns black, iron oxidizes and turns reddish, brown.
The reason, zinc prtotects iron from rusting is, it is more reactive and so the zinc uses the oxygen rather than the iron.

http://en.wikipedia.org/wiki/Lepidocrocite
If the material is stored or buried in a perfectly dry anerobic environment, in theory it will not rust.

Mineralization at Galena Hill consists predominantly of fine-grained galena and pyrite with lesser amounts of sphalerite and chalcopyrite. Electron microprobe studies have shown silver to be contained within the lattice of both galena and pyrite, with the bulk of the silver present within pyrite.
http://www.findarticles.com/p/articles/ ... _n15892155

I found the above article interesting.

If the material is stored or buried in a perfectly dry anerobic environment, in theory it will not rust.

That would help strengthen the hypothesis that this stuff was covered by 6-8' of gravel, which in turn was capped off with 8-10' of topsoil.

For me it depends on the ratios of the metals. Do you have an ore of iron, an ore of silver, or zinc the principle metal?

I'd hazard a guess that, because of the high level of magnetism, and the reddish brown rust, we're dealing with a primarily iron ore.

That would bring us back around to pyrite, I think...

Charlie Hatchett wrote:

For me it depends on the ratios of the metals. Do you have an ore of iron, an ore of silver, or zinc the principle metal?

I'd hazard a guess that, because of the high level of magnetism, and the reddish brown rust, we're dealing with a primarily iron ore.

That would bring us back around to pyrite, I think...

Your picture a few posts back the one in the article are very similar.
http://en.wikipedia.org/wiki/Pyrite

Any way you could "cook" one of those iron pyrite rocks to see if what comes out of it looks anything like what you keep finding?