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goldwind
Dredger
Joined: 13 Apr 2011
Posts: 136
Location: Gordon, Ga
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Posted:
Tue Jun 14, 2011 8:43 pm |
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Though it looks brown, it is black on the outside and inside..I was able to knock a chip off it. Put it on my grinding wheel..grinds smooth like metal(small piece)..turned gray..non-magnetic..any ideas?
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madhatter
Dredger
Joined: 28 Feb 2011
Posts: 2497
Location: NC eastern gold belt
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Posted:
Tue Jun 14, 2011 11:23 pm |
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possibly some kind of sedimentary rock maybe? |
_________________ Now where did I drop that 10lb nugget... |
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SamBurgin
Dredger
Joined: 22 May 2010
Posts: 605
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Posted:
Wed Jun 15, 2011 3:57 am |
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Lots of possibilities.
Streak test?
Hardness?
Specific gravity?
Help us help you.
Sam |
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madhatter
Dredger
Joined: 28 Feb 2011
Posts: 2497
Location: NC eastern gold belt
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Posted:
Wed Jun 15, 2011 5:02 am |
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try a streak test like sam said
just use a small square ceramic tile and scrape a chip of the rock or the rock itself on the tile.(just scrape it straight from top to bottum and post a good close up pic of it) |
_________________ Now where did I drop that 10lb nugget... |
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goldwind
Dredger
Joined: 13 Apr 2011
Posts: 136
Location: Gordon, Ga
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Posted:
Wed Jun 15, 2011 2:51 pm |
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Thanks guys..I could not get a good pic of streak test..left a gray streak..rock is gray inside..looks black when wet..can scratch it with a pocketknife.. lighter than quartz of the same size..sorry, I don't know anything about checking a rock..
This is a 10X pic of the chip..it has red,yellow,green and silver colors in it..thanks...gene |
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Charlotte49er
Dredger
Joined: 02 Nov 2010
Posts: 753
Location: Mint Hill, NC
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Posted:
Wed Jun 15, 2011 3:59 pm |
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My guess is slag. (Skim off from metal forming.)
But, I'm no Geologist. (I was a manufacturing Engineer.)
AND I stayed at a Holiday Inn Express last night!
Take it to a university, they could tell you in a minute. |
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SamBurgin
Dredger
Joined: 22 May 2010
Posts: 605
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Posted:
Wed Jun 15, 2011 4:24 pm |
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Likely an oxide of manganese...maybe Braunite, maybe not.
Manganese has a hardness of 6, which is harder than a pocket knife, unless the knife is hardened steel. So if regular steel it isn't manganese, nor braunite, even though it definitely has manganese stains on the outside.
Sam |
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Astrobouncer
Sluice Master
Joined: 13 Jul 2009
Posts: 1801
Location: SC Upstate
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Posted:
Wed Jun 15, 2011 5:23 pm |
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My guess is either andesite or basalt with some kind of olivine and pyroxene crystals accounting for the colors. |
_________________
Gork wrote: |
An old-timer in the Klondike told me "gold is where it ain't." |
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madhatter
Dredger
Joined: 28 Feb 2011
Posts: 2497
Location: NC eastern gold belt
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Posted:
Wed Jun 15, 2011 10:12 pm |
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Astrobouncer wrote: |
My guess is either andesite or basalt with some kind of olivine and pyroxene crystals accounting for the colors. |
I was thinking basalt too.. |
_________________ Now where did I drop that 10lb nugget... |
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goldwind
Dredger
Joined: 13 Apr 2011
Posts: 136
Location: Gordon, Ga
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Posted:
Wed Jun 15, 2011 10:51 pm |
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Thanks Sam, Astro, C49er and madhatt3r...took the names and been chasing down pics..got it narrowed down to basalt or gabbro..everything points to basalt...What is volcanic rock doing in middle Ga. ?...csu at pompano geology has a ignieous rock ID program online. I don't think ya'll need it but I used it to see what it would say...Basalt...Thanks again...gene |
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madhatter
Dredger
Joined: 28 Feb 2011
Posts: 2497
Location: NC eastern gold belt
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Posted:
Wed Jun 15, 2011 11:01 pm |
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goldwind wrote: |
Thanks Sam, Astro, C49er and madhatt3r...took the names and been chasing down pics..got it narrowed down to basalt or gabbro..everything points to basalt...What is volcanic rock doing in middle Ga. ?...csu at pompano geology has a ignieous rock ID program online. I don't think ya'll need it but I used it to see what it would say...Basalt...Thanks again...gene |
volcanic rock which made the earths crust and thermal vents too |
_________________ Now where did I drop that 10lb nugget... |
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goldwind
Dredger
Joined: 13 Apr 2011
Posts: 136
Location: Gordon, Ga
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Posted:
Thu Jun 16, 2011 10:37 pm |
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madhatt3r...that makes sense to me..I was thinking thousands of yrs ago...should have been Millions..thanks |
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madhatter
Dredger
Joined: 28 Feb 2011
Posts: 2497
Location: NC eastern gold belt
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Posted:
Thu Jun 16, 2011 11:02 pm |
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yeah...you can really get technical about it but thats basically it. |
_________________ Now where did I drop that 10lb nugget... |
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