Pyrite, Marcasite or Chalcopyrite?

[fuss]

I broke a part a large carbonate lake Michigan rock yesterday knowing there was calcite, pyrite and possible sphalerite in it since there was on the exterior though quite weathered. This little chip almost got tossed before I noticed the really nice colors and crystal forms. Look like standard tarnished pyrite or one of the others mentioned? I didn't do any tests to it, its too small and don't want to damage it, (its going into the collection). Thx.

Zoom in all the way to see the crystal details.

 

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[Trapper John]

Congrats on a nice specimen to add to your collection. My best guess is pyrite - but I am long on book larnin' and short on field identification skills.

 

[Steve1236]

I'd say Chalcopyrite, just a guess, nice find!

 

[Kray Gelder]

I'm not going to guess, but it's a nice keeper specimen. Really beautiful when you zoom in on it. Nice find!

 

[Steve1236]

I thought I saw tetragonal shapes at first glance plus you said Lake Michigan and copper popped in my mind but now I'm leaning pyrite, more cubic structure.

 

[fuss]

Im leaning with pyrite myself, ill snap a photo of the main rock later to show where I believe this chip broke off of. Also to show the fluorescent sphalerite.

 

[txusguy13]

Very nice find!

 

[fuss]

Here are some shots of the main rock, the matrix is a limestone/carbonate something with some pyrite and I believe sphalerite which is fluorescent orange, the stuff fluorescing blue/white is probably chert that has been weathered and beaten and the yellowish/buff is the same material just not weathered.

 

[avbmitch]

Geology types

Here are some shots of the main rock, the matrix is a limestone/carbonate something with some pyrite and I believe sphalerite which is fluorescent orange, the stuff fluorescing blue/white is probably chert that has been weathered and beaten and the yellowish/buff is the same material just not weathered.

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Hi All,
I'm hoping you are able to provide some insight for me on deep exploration
drilling for base metals. I'm involved in some exploratory deep
diamond drilling into a prospect which is brand new, never been explored before. We drilled 4 holes, with the deepest hole being about 600m deep. The Geology that we were hoping to encounter is that of IOCG bearing Geology, but my understanding is very limited on what that
means. The Geology that we have interpreted to have intersected is hematite altered granite, so my first question is, what is that and is
that a characteristic you would expect for systems containing base metals like copper and gold. This geology was adjacent to highly
magnetic diorite units, so second question, what does that mean? To expand on that a little, the target we drilled into was based off a
massive +1000 nT magnetic anomoly which is normally associated with
base metal discoveries.

Does the geology I have described so far give
any indication on the likeliness of a base metal discovery? I have
more follow up questions if possible, but i would really appreciate
some insight on the above Thanks