Another rock id please..

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Offline hvs

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Another rock id please..
« on: 13/07/2014 13:35:35 »
Hello, Im from upstate NY and collect native American indian stone tools.. I found these 2 stones last year on a old indian campsite and need help identifying them.. Stones are very heavy for there size and have a brownish crust around them thats flaking off in many areas. A magnet is attracted to the stones. Chondrules are present and under a mgnifying glass are black and smooth almost gem shaped..30 years of picking up stones ive never seen anything like these and hoping for some help.. Thanks Ron

 

 

 

 

 

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Offline hvs

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Re: Another rock id please..
« Reply #1 on: 13/07/2014 19:05:47 »
Anybody??

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Offline RD

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Re: Another rock id please..
« Reply #2 on: 13/07/2014 23:19:05 »
Possibly a combination like galena on pyrite ? ...

http://www.curriehj.freeserve.co.uk/republic.htm

Just a guess , you may be better off trying a forum dedicated to minerals
like mindat.org ... http://www.mindat.org/forum.php

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Offline hvs

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Re: Another rock id please..
« Reply #3 on: 14/07/2014 11:21:47 »
Thanks RD i think u might be right ill check out that other forum.. Thanks again. Ron

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Offline hvs

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Re: Another rock id please..
« Reply #4 on: 15/07/2014 01:56:33 »
Ok i washed one and cleaned it with a soft toothbrush and the brown crust seemed to be dirt and most of it came off. Since i have 2 i cut one in half [:(]..No clear crystals just black. The smaller stone weighs 139.5 grams larger one is 157 grams..

 

 
« Last Edit: 15/07/2014 02:01:04 by hvs »

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Offline RD

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Re: Another rock id please..
« Reply #5 on: 15/07/2014 10:03:10 »
Iron-ore is a colour-match ...

Quote
[attachment=18985]

The dark layers in this boulder are mainly composed of magnetite (Fe3O4) while the red layers are chalcedony, a form of silica (SiO2) that is colored red by tiny iron oxide particles.

http://www.amnh.org/exhibitions/permanent-exhibitions/... /banded-iron-formation
« Last Edit: 15/07/2014 10:07:49 by RD »

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Offline hvs

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Re: Another rock id please..
« Reply #6 on: 15/07/2014 17:36:35 »
Very interesting RD, Thanks.. Take a look at what others think on another forum i posted on..
newbielink:http://www.mindat.org/mesg-11-329033.html [nonactive]

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Offline RD

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Re: Another rock id please..
« Reply #7 on: 15/07/2014 21:03:14 »
Very interesting RD, Thanks.. Take a look at what others think on another forum i posted on..
http://www.mindat.org/mesg-11-329033.html

Pic r2 does look like it has glacial striation, (parallel grooves), on the flat surface.
I don't think the wear would look like that if it was an artifact ground-down for pigment.
« Last Edit: 15/07/2014 21:12:57 by RD »

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Offline hvs

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Re: Another rock id please..
« Reply #8 on: 16/07/2014 16:40:21 »
Polished it up a bit and it sure looks like copper inside..



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Offline Bass

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Re: Another rock id please..
« Reply #9 on: 16/07/2014 17:43:53 »
Have you checked this with a magnet?  What about hardness?
Native copper is ductile and malleable- so if you try to scratch it with a knife or sharp point, it should leave a groove with little to no material coming off the specimen.
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Offline hvs

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Re: Another rock id please..
« Reply #10 on: 16/07/2014 21:03:52 »
Its very hard like steel. The copper seems very hard just like the material around it but it does scratch . i figured the copper would be soft but its not as soft as one would think.. When i hang a small magnet on a string it does stick to the stone.. "Just lightly pulls to the stone."
« Last Edit: 16/07/2014 21:06:15 by hvs »

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Offline Bass

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Re: Another rock id please..
« Reply #11 on: 18/07/2014 00:51:45 »
given the similar hardness and the magnetism, my guess would be magnetite weathering to hematite.
Old enough to have a grandson
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Thirsty enough to find a pub