Fools Gold

[Darshevo]

I got the following material on a recent outting (actually, my girl friend found it while I was playing around in the creek). I initially thought it was pyrite, but I have picked pyrite up before on rock hounding adventures. I have a trusted ally who (judging from the pictures) thinks it is likely Chalcopyrite. Figured since a number of you are running into this kind of stuff on a daily basis I would get a second opinion before it gets labeled and goes into my girl friends daughters rock collection.

Under the right light it has a greenish tint.

The first picture is as I found it. The 2nd is the mineral removed from the rock.

-Lance

[jog]

Can you scratch it or pound a piece flat? Is it soft or brittle?

[Darshevo]

Its quite brittle. I was hoping to remove it as a whole, but is broke up as soon as I went to work on it with my pick

-Lance

[jimmygoat]

Hello darshevo, I agree with your trusted ally. Jimmygoat

[Eu_citzen]

If you can scratch it with a knife, chalcopyrite.

[FiresEye]

Its quite brittle. I was hoping to remove it as a whole, but is broke up as soon as I went to work on it with my pick

-Lance

?
Was this rock collected from a gold bearing area? If it was, than there is surely micro gold trapped within the pyrite and quartz... perhaps even small flake gold.. ... Pyrite and gold go hand in hand in some locations, and it goes beyond just micro..

[FiresEye]

If you can scratch it with a knife, chalcopyrite.

Ugh... I need to research the relation of gold bearing minerals because I'm loaded with colorful specimens pulled tight from the lock of the rocks in a guaranteed gold bearing stream..

I KNOW there's gold in the rocks, I just don't know if it's mostly micro or mostly flake vein...

My first step is a nice Iron/steel Mortal and pestle

[Darshevo]

I have been told by a few people who seem to know their stuff that I should get that specimen assayed (their opinion that there should be gold within the pyrites matches yours). I;m neck deep in a remodel project right now that should be wrapped up towards the end of the week and I will have more free time. My first step will be crushing up and panning a small sample to see what turns up. The area is a gold bearing area (was quite productive 100 years ago) We're working way up the drainage from there though, been following those white rocks (believed to be a quartz dolomite mix) to see if we can find where they are coming from

-Lance

[Tuberale]

The greenish tint to the crystaline golden-colored material supports chalcopyrite in my opinion. But the material the arrow is pointing to in the photo is not chalcopyrite. I'm not sure what it is: galena (lead sulfite) certainly a possibility in a pyrite-producing area. Might want to do a streak test on that portion for silver as well.

[Gobpile]

Why not just crush some and pan it? I have done this with success.Also use a good magnifier and inspect the specimen.