Today's Find, Calcite and something new

[th30utkast3d]

Broke some pieces of the big rock I got today. tryed to take better pictures. So here is what I got. I used some links that were provided by someone to see if I could figure out what some of these are.

Pyrite?



On this picture I was wondering if under the calcite is there more pyrite? It does look darker in the center




I uped the contrast so it was easier to see how dark the inside looks

[scottr]

marcasite

[lauriesrocks]

I agree, marcasite.

[Ryan]

Marcasite and pyrite are confused for each other all the time. There are radiating "suns" of Marcasite that form in coal mines in the midwest (Illinois I think) and I hear people call them pyrite suns all the time. They have the same formula: Iron Sulfide FeS2, just pyrite has a more distinct crystal shape and marcasite is more brittle and crumbly.

Nice pieces though, for a noob you have some pretty good luck finding fun specimins.

[th30utkast3d]

Could be just beginners luck. But having a big family does make it a little easier. It is a win win for my family. Kids get the exercise and get to collect cool stuff. Man I thought I had this one. I cant wait to get my books. I ordered some nice books to help me learn.

[Dicky the Rockhunter]

that might need some more surgical breaking ! Really nice specimens.

Dicky

[th30utkast3d]

Is it worth trying to break open and see what the inside looks like? Someone posted that some kinds of acid would dissolve the calcite. would it leave the marcasite? I have a few with really dark centers and I would not mind trying but dont want to mess it all up.

[sunshine]

I don't recall the detention time or acid concentration but have cleaned marcasite using HCl in the past. Practice on a sample first, you don't want to ruin a center shelf specimen. Looks like you found a honey hole for a beginner!
I've included a photo of an epidote, actinolite specimen with the calcite removed.

x

[sunshine]

If you like the display don't do anything. In some situations the calcite may be holding the specimen together. There's a good chance nothing's underneath.

Good example is North Carolina's Cranberry Mine. Hint! Hint!, About one in five samples, hidden under the calcite are clusters of small perfect pyrite cubes.

[Barrett]

Pictures are much better in this thread, outkast, you can see the detail much better. Well done!