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Post by tkrueger3 on May 12, 2011 23:12:35 GMT -5
I've never seen anything like this before. It's an extremely dark green - it really looks black - with very shiny gold-colored streaks all through it. The raw surface of the rock feels grainy, but the sawn surfaces feel almost like "oily" is the best way I can describe it. It's about a MOH's 6, and it makes a heavy black streak on white porcelain. I'd sure like to know what it is, if anyone can id it for me. 2 pictures - the first with flash, the second with incandescent lighting only, which turned the whole picture sorta sepia for some reason. Thanks, Tom
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Post by tkrueger3 on May 13, 2011 15:09:26 GMT -5
Wow! Nobody has anything to say? I guess I musta stumped the panel!!! ;D
Tom
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Sabre52
Cave Dweller
Me and my gal, Rosie
Member since August 2005
Posts: 20,466
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Post by Sabre52 on May 13, 2011 16:21:10 GMT -5
Got me stumped. I was going to say Apache Gold which is a dark shist with metallic chalcopyrite inclusions. Have also seen a similar form which seems to have serpentine as it's base rock but that 6 mohs hardness seems a bit hard for either material. I think both are usually more like a mohs 4 1/2-5.....Mel
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Post by tkrueger3 on May 13, 2011 16:45:14 GMT -5
Thanks, Mel - I'm pretty sure about the 6 mohs - I used my little "test kit" and that's where it landed. I could be wrong, of course, but it's held pretty true with other materials where I knew the mohs before I tested.
Whatever it is, I'm going to try cabbing it and see what happens. I have a suspicion that it will only take a matte finish, and probably the gold-colored streaks will prove problematical - I'm guessing they will flake out.
Tom
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Sabre52
Cave Dweller
Me and my gal, Rosie
Member since August 2005
Posts: 20,466
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Post by Sabre52 on May 13, 2011 17:14:45 GMT -5
Tom you may be surprised. Both the Apache gold type materials I've encountered took a real nice shine and yours is pretty hard. metallic ores in that pyrite/chalcopyrite group often will take a mirror polish. The Hornitos poppy I used to mine had gold bearing pyrite included and it took a heck of a fine polish and didn't even rust because of gold content.....Mel
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pezzottait
off to a rocking start
Member since March 2011
Posts: 23
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Post by pezzottait on May 14, 2011 11:28:40 GMT -5
I think it is a dumortierite!
Sigi
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MikeS
fully equipped rock polisher
Member since January 2009
Posts: 1,081
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Post by MikeS on May 14, 2011 15:26:17 GMT -5
I would suspect some sort of serpentinite with mica inclusions...
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Post by tkrueger3 on May 15, 2011 22:10:35 GMT -5
Just a little update - I've been slicing this thing, and it has turned the oil black, like hematite would. Could it be hematite with pyrite inclusions? I don't suppose it would be possible for the gold colored inclusions to be ... uh ... gold? Nah! Fool's gold, maybe. ;D
Tom
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pezzottait
off to a rocking start
Member since March 2011
Posts: 23
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Post by pezzottait on May 16, 2011 9:32:19 GMT -5
A dumortierite from the Champion mine, Nevada, for comparison only! Sigi Attachments:
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Post by tkrueger3 on May 16, 2011 11:05:33 GMT -5
By golly, it sure does look the same as that dumortierite! Thanks!
Tom
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Post by tandl on May 16, 2011 17:56:08 GMT -5
That looks like pyrite, pyrite turns black when cut too . at a hardness of six ,and green color i would say a schist . A nice example too .
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