Help please

[Dinkum]

Can anyone have a stab at what mineral is in this photo please?
I am in the gold fields in far North Queensland and found these nuggets.
On breaking one open it looks very silvery. They are non magnetic and give
a nice tune. I guess they are lighter than gold.
Thanks

 

[BigWave]

Please try them with an ohm-meter and advise.

 

[Dinkum]

Thanks Big Wave
One piece reads about 5 ohms in 5 mm. Thats a very rough measure though

 

[Ward69]

Ha Dinkum. Have same. Here in warwick.

. After sitting in salt and vingar. I can squeeze with pliers I'm thinking a slag from a clean up Mercury with something. Or lead with something. Ward69

 

[Ward69]

I need stop putting things in my mouth thou.

 

[Dinkum]

G,day Ward69
The stuff I have is hard to bite.!!! So is probably different to what you have.
It is also much brighter than that shown in the image.

Old habits die hard. Chewing solder when a kid must have had an effect on me as I have been seen trying to dig holes to China!!!

 

[Dinkum]

G,day Folks

The closest I have come to finding out what these nuggets might be is molybdenite, although they do not exactly compare.
Attached is a better photograph showing how silvery the actual surface of the cracked nugget is.

 

[Dinkum]

Another suggestion has been Antimony.
Any ideas would be appreciated.

 

[user 4386]

Are you sure it is not two different metallic minerals (say stibnite in pyrite, or stibnite in native antimony), perhaps with a crust of another oxide mineral?. You can easily dig into stibnite with a pen knife blade (even a copper coin). Or vice-versa, it will smear onto a copper coin without scratching it.

Always best to use mineral names. eg antimony can be the metal, or in the sulphide stibnite, or in oxides such as cervantite. If the metal we tend to say "native antimony" which is the naturally-occurring mineral. Strictly we should also say native gold, but it would use up half this blog....

 

[Dinkum]

Thanks Goldierocks.

So much to learn and so
Little time to learn it.!!!

 

[user 4386]

The only thing is that it would not be a single mass of stibnite alone - stibnite is not a conductor. Looks a mixture to me, but difficult to tell from a photo...

 

[Dinkum]

Thanks for that.
I will see if I can get it spectrographed. If that's the right word.

 

[jethro]

Stab in the dark here. Sylvanite. https://www.mindat.org/min-3849.html

 

[user 4386]

I doubt that - sylvanite is so soft you can scrape it with your fingernail and extremely heavy. It is quite rare and being a gold mineral, valuable. There is a flame test for it, but if it were sylvanite you would need to be careful as tellurium is very toxic. It is highly improbable. It is not cheap to test anything, whether chemically or mineralogically (eg XRD) - you need a mineralogist friend. Or try the museum....

 

[Hunting the yellow]

G,day Folks

The closest I have come to finding out what these nuggets might be is molybdenite, although they do not exactly compare.
Attached is a better photograph showing how silvery the actual surface of the cracked nugget is.

https://www.prospectingaustralia.com/forum/img/member-images/10811/1528945811__20180614_130306.jpg

way too bright for antimony or stibnite I know this because I mine it daily and its darker than this and a more grey colour rather than silvery I would say its molybdenite a good way to make sure is try and find old history reports in the area that state what minerals are near or at where you found it if it lists molybdenite then good chance its that. and test it with your finger if you can poke your finger nail into it and its really soft 2 or 3 on the hardness scale then its molybdenite. antimony you can only scrape with a fingernail not penetrate your nail into it.

 

[user 4386]

G,day Folks

The closest I have come to finding out what these nuggets might be is molybdenite, although they do not exactly compare.
Attached is a better photograph showing how silvery the actual surface of the cracked nugget is.

https://www.prospectingaustralia.com/forum/img/member-images/10811/1528945811__20180614_130306.jpg

way too bright for antimony or stibnite I know this because I mine it daily and its darker than this and a more grey colour rather than silvery I would say its molybdenite a good way to make sure is try and find old history reports in the area that state what minerals are near or at where you found it if it lists molybdenite then good chance its that. and test it with your finger if you can poke your finger nail into it and its really soft 2 or 3 on the hardness scale then its molybdenite. antimony you can only scrape with a fingernail not penetrate your nail into it.

Yep, good advice. Colour in a photo is a function of how the photo is taken, so be a bit wary about brightness - if true colour you could be right. Much the same issue with molybdenite though - it tends to be pretty dark. https://en.wikipedia.org/wiki/Molybdenite

We really need to know hardness (and streak)

 

[Dinkum]

Thanks for all your help folks.
With an amature look in the bush it won't scratch vey well and doesn't seem to streak.
I will probably get it professionaly checked and, if so, will report the outcome.
In the meantime will keep looking for some proper yellow stuff.!

 

[Dave79]

Maybe see if your local scrap metal dealer has an XRF machine?

 

[Dinkum]

Thanks for all your help folks.

Yes the XRF machine says its Sb or native antimony.