Identity HelpID of Ag and Au mineral inclusions in luzonite
The deposit is high-sulfidation epithermal gold-silver. Lots of enargite, luzonite, pyrite. Silver has always been recognized as being associated with the Cu minerals, but silver minerals (to my knowledge) have not been identified.
These are not polished mounts, and I realize that limits the usefulness of these results.
The first inclusion contains gold and silver, and uytenbogaardtite was offered as a possibility. Multiple scans were taken with similar results:
The second spectrum is of a mineral found abundantly disseminated through another sample of luzonite (with minor famatinite, enargite, and tetrahedrite, based on XRD):
A silver sulfosalt was offered as a possibility.
I am wondering if these spectra could have picked up elements (Cu, Sb, As, Te, S) from the surrounding luzonite. If so, perhaps the first spectrum could be a silver-gold telluride with luzonite contamination, and the second spectrum could be acanthite or stromeyerite with luzonite contamination?
Any other guesses?
Thank you,
Kyle
I presume these suggested minerals occur at that locality? 49 looks like a mixture and 01 not. In the case of 01 it should be easy to distinguish acanthite from stromeyerite visually. In the case of 49 uytenbogaardtite seems like a reasonable choice if you cannot see any native gold. Thanks Reiner. No, there is little published on the deposit, and almost nothing regarding mineralogy. One geologist who did work on material from there said he did not identify any silver minerals other than electrum. Old reports on the deposit mention silver minerals, but I don't trust them as they are vague and there appears to have been confusion between this mine and another nearby one.
These inclusions are tiny (perhaps in the 20-100 micron range) and dispersed in Cu sulfosalt, and I am not the one doing the analysis, so unfortunately, I don't think trying to isolate an inclusion and look at its characteristics is practical! I did not know they were even present until the analysis was done.
Kyle 
Kyle, there is no way to ID any specific minerals based on these EDS spectrum, don't assume these represent a single mineral, most likely these are complex mixtures - a polished mount would be needed together with some backscattered imaging to see contrast differences between the minerals in the SEM. Then each region can have a spot analysis to get composition. Back in college we crushed similar samples to -60 microns, and used heavy liquids to separate the minerals by density - you would need a largish sample and equipment to do so, but could help to enrich a fraction for improved analysis. 
Thin polished samples will give a good results. I am working with them on a daily basis. If you have noch access to prepair them yourself there are several companies out there who can do it for reasonable prices. And yes you need back scattered method. Good luck its mostly very interesting. 
Hi Kyle,
Reading your first lines, the thought came to me that similar problems expected me. :-)
With ore samples of a similar paragenesis from Bulgaria.
http://www.mindat.org/loc-16254.html
Enargite-Luzonites (as inclusions) do not appear to be optically separable.
Tellurides are something particularly fine.
Unfortunately at the moment no time for my samples. The future will show it.
Because we are on the topic : I am looking for a sample with Kostovite (preferably from Chelopech) in the purchase or exchange.
Have a nice day
Marcus Hello Kyle,
On the scale you are talking about, like others have suggested, you will need polished sections unless you can isolate an unusually large monomineralic grain. Personally when it comes to material that size it stops being fun and becomes work so I avoid such material. In other words if I can't isoloate a single grain at 40X I don't bother with it and stop looking. But then to each his own. Interesting material never the less and I would keep looking because there is a chance you could find an unusually large grain. For example froodite almost always occurs in micron size grains only observable in polished sections but sometimes you get lucky and can find something like this : http://www.mindat.org/photo-587166.html I have an update. I had a slab made of the material with the silver-bearing inclusions (second analysis above). Electron images and spot analyses show that these inclusions are indeed acanthite, with the copper, arsenic, and antimony (which appeared in the EDS analysis above) probably contributed by the surrounding copper sulfosalt.
Here is an electron image of one analyzed area:
Two analyzed acanthite inclusions are labeled. The surrounding gray is copper sulfosalt (probably luzonite, based on composition and XRD of same specimen), which also has some silver (~1%).
These acanthite inclusions are irregular in shape and there does not appear to be any pattern to their occurrence. Any suggestions on how to interpret the paragenesis here? Am I correct in assuming the acanthite must be hypogene and not supergene? This assumption is based on: 1. No identified supergene minerals associated with the acanthite, and 2. The acanthite does not follow any obvious fracture in the copper sulfosalt, but rather is disseminated through it. Is it more likely that the acanthite was deposited at the same time as the copper sulfosalt, or did one likely precede the other?
Thanks,
Kyle
