Enargite ???

[How Lucky]

Was hoping someone could properly identify this sample. It came out of the hills of York county Maine. The mine is no more than a trench dug into a hillside and it has loose stones like you see here scattered in the dirt. They range in size from 1/4" to 2' size rocks. The mine is known for copper, arsenic and pyrite. So my guess is Enargite. What name would you put to the sample?

 

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[Eu_citzen]

My first reaction is: "host rock". Do a streak test and see if a knife will scratch it.

 

[How Lucky]

You are right about calling it a host rock but I am looking for a more defined name. I shy away from doing any type of testing because of the arsenic content of the samples. I'm hoping with the clues I've given and the pictures, will get me the name of this mineral.

 

[Eu_citzen]

Then you'd be better of reading geological reports on the mine in question.
USGS or related authorities might have visited it, of course you need to know it's name to research it.

 

[hvacker]

First impression was bubbly basalt but just a guess from a picture.

 

[Eu_citzen]

First impression was bubbly basalt but just a guess from a picture.

vesicular basalt? Close, but I see something which looks feldspar-ish to me. Not quite so mafic, I think.
Might be wrong and my eyes are fooling me.

 

[How Lucky]

I think the rock surface is pot-marked because of dissolved sulfides. A number of the stones are oddly shaped.

 

[Eu_citzen]

I think the rock surface is pot-marked because of dissolved sulfides. A number of the stones are oddly shaped.

Quite possible. If so typicall the "holes" may appear to be square, retangular etc. Or simply put; looking like the original sulphides which occupied it.
Pyrite for example often leaves cube-shaped holes.