Western Montana Chalcocite?

[salvageon]

My friend built a road on his property West of Missoula, MT and came across some very narrow veins in the slide rock. I have been told that it could be Chalcocite which is a copper ore and would like another opinion or confirmation. I have looked at pictures and some found around Butte looks similar. Odd looking stuff for copper. Any ideas? Very hard and non magnetic. Thanks

 

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[IAMZIM]

It looks more like galena or lead to me, but you say it is hard, and galena and lead are soft. I have alot of mine samples from here in Butte, but my Chalcocite does not look like that. I am however not an expert. Take it for what that's worth, lol! You could try to have it assayed, then you would know for sure.

 

[salvageon]

Thanks for the input. We Montanan's need to get together sometime and swap stories.

 

[Dragontomb]

I sure wish I could find a nice piece of sulphide ore like you got there. Fun to identify and figure out. There aren't many massive sulphide deposits in BC, especially with the copper sulphide concentration. Maybe there is enargite mixed in there as well.

 

[Eu_citzen]

I'd also think Galena. Can a knife scratch it?

 

[salvageon]

No it won't scratch and the vein is very thin. What you see is all there is on this specimen. I'll ask my friend if there are thicker veins this spring.

 

[Whiplash00]

I have that too on my property. Glacial deposited here of course. It's sandstone with iron oxide, I was told by a mineralogist that's how it grows.

 

[Eu_citzen]

Iron oxide (hematite or magnetite) don't show cleavage like this particular specimen.

There are not a whole lot of minerals I can think of that look like this and aren't scratched by a knife. Ilmenite might be a possibility.
Could you do a streak test?