FMF - Friends of Minerals Forum, discussion and message board

[naturalgoldau]

Hi newhere and new to actaully looking at rocks properly,... my grandpappy left me this rock..... my search to understand it has lead me to this site..... heres a few pix, the rock weighs about 400Kgs. Any Ideas on what it could be.. would be cool...
I come from Kalgoorlie in Western Australia. I love photography and I do think this is the most unusual and photogenic thing I have ever seen....

I am tempted to break it all up because it appears to be snow white on the inside. It has these shiny bits all through. and someone mentioned telluride ores... which is feasible.I would like to see if the best mineral site I can find on the planet, withcombned knowledge , can give a few secret tips in the right direction.

is it worth breaking up?

[Jordi Fabre]

Really hard tell you something just with these photos, but Kalgoorlie name means usually telluride and by your photos we can't discard this possibility.
Honestly I think that the best to do is to send some parcel to an analyzer (Excalibur and John Attard come to my mind) and after the result of the analysis and if the silver-colored crystalline faces are a telluride, then it could be a good idea be back to this forum to consult what would be the best to do with your really large rock.

First step is to know what you have exactly, and depending the result then discuss other possibilities.

Jordi

[naturalgoldau]

Thanks for your reply. I will analyse what minerals are contained and come back here to see what the better options will be.
auscoot

[naturalgoldau]

Hi Again

I got a local assay done with a limited acid test and I tested for Te, Au, Ag. Sb.

Results revealed:

PPM:
Ag : 0.24
Sb : 0.683
Te: <0.5
Au: <0.1

Please Correct me if I am wrong, but i think there is other elements I could test for as well.

I am happy to send samples overseas to the places you provided, though I am really preferring to keep it local.

So, with this information.I did send a very poor sparse sample, and if I sent one of the rich samples, wouldn't it show a higher level of density?

What else could I submit for sample test, IE lead, mercury?

Finally is there a way to dissolve quartz to reveal the specimen of mineral inside without having it damaged. Acid bath or similar

Thanks again.

[Pete Modreski]

Dear naturalgoldau,

Since your first assay did not show significant gold or Te, it's not encouraging. I must admit, I do not know what "a limited acid test" means, in connection with an assay.

Presumably, the sample you had assayed contained at least some of the slivery telluride-like mineral grains. Traditional practice when prospectors have samples assayed, of course, is to start by sending what appears to be the highest-grade sample possible to the assay lab, even if they know it is not representative of the bulk of their ore; that way they will find out at least what the maximum potential value is, and of course for attracting investors, it doesn't hurt to have a spectacularly high assay value to impress them with.

I would still suggest that you contact either of the two sources Jordi mentioned, John Attard or Excalibur Minerals, and send them a small sample not for bulk analysis, but to confirm the identity of just the silvery mineral grains; then you'll really know if you have Au-Ag telluride minerals, or something less valuable. The cost for their analysis will be modest. Here are addresses by which you can contact them:

Well, I just checked at Excalibur's website, https://www.excaliburmineral.com/
and I'm afraid it says,

"Our SEM/EDS laboratory is not accepting material for analytical confirmation at this time due to excessive backlogs and demands on the system! "

so you if you wish to try contacting John Attard:

https://attminerals.com/ attard@attminerals.com

Although there are many assay labs all over the world that can do bulk assays for precious metals, there are only a few labs or persons worldwide who have the equipment and are willing, to do specific analysis of individual mineral grains to determine what they are; and I think that this is what you need, because what makes your sample hopefully special and valuable is not its bulk content of gold as "ore" (you are not planning to have it smelted for its gold value), but its potential interest as a large sample of the distincitive telluride minerals from Kalgoorlie, so you really should find out whether those minerals are present.

best of luck,
Pete Modreski

[GneissWare]

Dissolving quartz is fairly simple (although not entirely trivial from a safety standpoint). However, you need to know the mineral that is encased in the quartz to determine its solubility. So, before you pull out the HF or ammonium bifluoride to remove the quartz, you should have the metallic stuff analyzed, otherwise you may end up with silica-metal soup, and no specimens.

[naturalgoldau]

Hi Ho Hi Ho its off to Attards we go.

Thnaks for the advice will keep you updated.

sj