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Author Topic: Can anyone tell me what this rock is?  (Read 5155 times)

Offline smerik

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Can anyone tell me what this rock is?
« on: 25/07/2009 22:05:10 »
I noticed this rock in our river rock landscaping, it really stood out because all of the other rocks that it was touching were turning black on the edges that were touching this rock. i picked it up and noticed that it was pretty heavy. also, some parts of it appeared to be dissolving into gray dust. when i tapped on it with a screwdriver, a piece broke off, revealing sparkly, gold colored crystals inside. the gray in the pictures is powdery. it's been just sitting on a shelf in my garage, and the gray areas seem to be growing. also, after handling it, my hands have a strong, kind of metallic odor. any ideas?

newbielink:http://smg.photobucket.com/albums/v610/smerik/?action=view&current=IMG_5771-1.jpg [nonactive]

newbielink:http://smg.photobucket.com/albums/v610/smerik/?action=view&current=IMG_5772.jpg [nonactive]

newbielink:http://smg.photobucket.com/albums/v610/smerik/?action=view&current=IMG_5773.jpg [nonactive]

newbielink:http://smg.photobucket.com/albums/v610/smerik/?action=view&current=IMG_5774.jpg [nonactive]

newbielink:http://smg.photobucket.com/albums/v610/smerik/?action=view&current=IMG_5775.jpg [nonactive]

newbielink:http://smg.photobucket.com/albums/v610/smerik/?action=view&current=IMG_5777.jpg [nonactive]

newbielink:http://smg.photobucket.com/albums/v610/smerik/?action=view&current=IMG_5778.jpg [nonactive]


 

Offline JimBob

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Can anyone tell me what this rock is?
« Reply #1 on: 25/07/2009 23:28:44 »
OK - could be a couple of things - where do you live and what type of rocks are dominant in your area? I am looking for "limestone" "sandstone" "granite" or something like that. FIRST impression ONLY is that it is a fine-grained pyrite nodule but depending on what is around you it could be a couple of other things.
 

Offline smerik

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Can anyone tell me what this rock is?
« Reply #2 on: 26/07/2009 00:31:38 »
I live in northern Indiana, I believe there is a lot of Limestone.
 

Offline Bass

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Can anyone tell me what this rock is?
« Reply #3 on: 26/07/2009 05:00:20 »
No doubt the rock is mainly sulfide- like JimBob, I would suspect pyrite, especially with the white sulfate minerals in the photos.  However, strange that it weathers black- which would suggest high manganese concentrations. (even stranger, if just pyrite, that it would stain adjacent rocks black).  Maybe you have a Mn nodule- the shiny sulfides could be pyrrhotite, pentlandite, even with some cobaltite.
http://www.newarkcampus.org/professional/osu/faculty/jstjohn/Mn-Nodule/Mn-Nodule.htm
 

Offline Geoman69

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Can anyone tell me what this rock is?
« Reply #4 on: 03/08/2009 21:01:24 »
My first advice would be to wash your hands after handling it, could be some Arsenopyrite in there.  We might be able to narrow it down by doing the following:

Stick a magnet against it, is it magnetic?

Smack it with something, does it smell like garlic?

If you happen to have a streak plate, or some other ceramic plate you don't mind scratching, try to get a streak and tell us what colour it is.
 

Offline JimBob

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Can anyone tell me what this rock is?
« Reply #5 on: 04/08/2009 02:38:26 »
You can always tell a Canadian by the way the spell color - the CORRECT way to spell the word.

Oh by the way - WELCOME TO THE SITE!
 

Offline Chemistry4me

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Can anyone tell me what this rock is?
« Reply #6 on: 04/08/2009 04:16:57 »
Welcome Geoman69! :)
I think you have finally found the right forum! Just watch out for JimBob. He does go a bit haywire when he's off his medication ;D

-----
Notice him here talking cleavage.
« Last Edit: 04/08/2009 04:20:04 by Chemistry4me »
 

Offline Bass

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Can anyone tell me what this rock is?
« Reply #7 on: 04/08/2009 04:56:36 »
Thank you sir!  I've been looking for a good geology forum for years, and I stumbled across this looking for an answer to a physics question :) .

And yes, I am Canadian.  Saskatchewanian to be precise.

Nice to have you aboot, eh? [:I]

Welcome to the forum.  Hard-rocker or soft-rocker?  If the latter, I'm sorry- (JimBob is under my strict rehabilitation!)
 

Offline Geoman69

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Can anyone tell me what this rock is?
« Reply #8 on: 04/08/2009 07:19:16 »
Well, the money/jobs around here are in soft rocks, I find hard rocks to be quite interesting, but I suppose that my passion is for Geophysics.

How's that for dodging the question?  ;D
 

Offline JimBob

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Can anyone tell me what this rock is?
« Reply #9 on: 05/08/2009 03:48:35 »
wiggle picker! or worse - a reflector guy - Dam!


Well, grin and bare (sic) it.

Bass thinks he is rehabilitating me. I know better. Living in Montana, he is almost a Canuck and a solid hard-rock mining geologist to boot. Under the guise of cooperating with him I am secretly luring him into a position where he will, by necessity, need to learn to drill an oil well.


Mwahhaahahhahahhahahahahha!



  
 

Offline Geoman69

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Can anyone tell me what this rock is?
« Reply #10 on: 05/08/2009 07:33:09 »
Haha, sometimes you just want a darn quantitative answer to a question, Geophysics scratches that itch for me.  Yeah, I know that it's an approximation, don't rain on my parade  ;D .

For the record, I love Montana, how boot that elm coulee field  :D .
« Last Edit: 05/08/2009 07:36:50 by Geoman69 »
 

Offline JimBob

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Can anyone tell me what this rock is?
« Reply #11 on: 05/08/2009 20:11:07 »
IT'S GREASE! NUF FER ME.
 

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Can anyone tell me what this rock is?
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