FMF - Friends of Minerals Forum, discussion and message board

[Stone Mania]

What crystal habit does this piece of pyrite have? Would it be described as massive? Anything else you can tell me about his piece would be greatly appreciated.


Many thanks,

Laurence

[Carles Millan]

[alfredo]

Also, check it with a magnet to see whether it's really pyrite, or might be pyrrhotite.

[Pete Modreski]

Yes, definitely, we'd just call it "massive".

Looks like it's criss-crossed by veins & patches of some other, dark mineral, probably some other sulfide. Could be any of a great number of things--galena, black sphalerite, bornite, molybdenite, chalcocite... and probably no easy way to tell what that might be, unless you can tell that it has good cleavage (galena or sphalerite), is very soft (molybdenite), etc.

[Stone Mania]

Thanks guys for your replies. Checked it with a magnet and can feel no magnetism at all.

[alfredo]

In that case no pyrrhotite, and probably indeed pyrite as you thought, and perhaps also including other sulphides as Pete said.

[Stone Mania]

Thanks Pete, it's definitely criss-crossed by veins of a dark mineral. Difficult to see any obvious cleavage. When I bought it I was told it was pyrite and the guy I buy from knows his stuff but I can't remember everything he told me about it. It's been locked away for some time and has only just come out to be photographed and added to my website.

Thanks again for the info, greatly appreciated.

[Stone Mania]

Thanks Alfredo, appreciate the info.