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Post by snowmom on Dec 17, 2014 8:39:11 GMT -5
can't help myself, while things melted over the weekend I hit two lake Huron locations. Found some mysterious stuff. This may be the most mysterious of all. first I saw this, a black rock with a rough surface and red flecks, it has two very small pieces of breccia or perhaps it is porphyry. It is hard and dense, glass will not scratch it. A magnet jumped to it when it was placed nearby.
then when I got it home and washed it off, I noticed this. tiny colored spheres or pisolitic areas of red and green. there is some streaking of of red in places on the stone so I am unsure if this staining or melted rock (the red). The other spheres which are observable with the naked eye and most smaller than the head of a pin, are the same green that we associate here with epidote.
looking further with the help of my magnifier light (and sorry for the glare on the pictures, I would love to get a macro lens, but this is the best I can do for now) You can see some pits which don't seem to be filled....
but wait!
those pits are filled with tiny crystals!
Some things are just too hard to understand. This might make a nice sparkly -dotted slab/cab some day, eh?
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Post by fantastic5 on Dec 17, 2014 9:37:35 GMT -5
I sure hope Santa brings you a saw! Not seeing your finds cut is painful!
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Post by broseph82 on Dec 17, 2014 11:02:47 GMT -5
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Post by snowmom on Dec 17, 2014 13:06:39 GMT -5
oh yeah, Please please please Santa bring me a BIG saw... it does drive me crazy to have so much stuff I want to cut. I will probably have to send my rocks forever to somebody and ask for a slab back in exchange in order to see what's inside. Thanks to so many of you for doing this for me in the past, I have a much better understanding of the things I find here. I don't think cutting this would help figure it out, but it might be pretty, and very very different as a slab or cabs. Thanks for the good wishes Ann, and for the link, Jimi.
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Post by 150FromFundy on Dec 17, 2014 17:26:10 GMT -5
Here's a guess...
The rock is Epidosite which contains a lot of Epidote. The Epidosite is black, the Epidote is pistachio green.
Epidote is an iron-rich orthosilicate. The iron-rich makes it magnetic. The orthosilicate makes it harder than glass.
The red may be hematite, or may simply be rust on the oxidized surface that does not run through the rock.
Good luck with the saw. Rocks are even neater on the inside.
Darryl.
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Fossilman
Cave Dweller
Member since January 2009
Posts: 20,676
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Post by Fossilman on Dec 17, 2014 17:59:33 GMT -5
Cut it,cut it,cut it.....
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Mark K
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Member since April 2012
Posts: 2,563
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Post by Mark K on Dec 17, 2014 18:30:55 GMT -5
oh yeah, Please please please Santa bring me a BIG saw... it does drive me crazy to have so much stuff I want to cut. I will probably have to send my rocks forever to somebody and ask for a slab back in exchange in order to see what's inside. Thanks to so many of you for doing this for me in the past, I have a much better understanding of the things I find here. I don't think cutting this would help figure it out, but it might be pretty, and very very different as a slab or cabs. Thanks for the good wishes Ann, and for the link, Jimi. I bet you could find a used 10 inch tile saw for 100 bucks. Heck, I think my first real trim saw was around 100 bucks.
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Mark K
Cave Dweller
Member since April 2012
Posts: 2,563
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Post by Mark K on Dec 17, 2014 18:45:45 GMT -5
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Deleted
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Post by Deleted on Dec 17, 2014 21:28:31 GMT -5
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Post by snowmom on Dec 19, 2014 18:21:49 GMT -5
I know there was a huge range of volcanic activity in a line from Minnesota to the east back when the UP and the Niagran ridge were formed and they are finding kimberlite pipes all over the UP,I think at least a dozen now documented... wouldn't surprise me a bit if there were lots of kimberlite pipes under the Great Lakes as well. The crystals are so tiny I have not been able to tell for sure, I think they are clear and reflecting the black matrix but they could be black. I had thought the red might be hematite due to the magnetic nature of the rock. Cool if it is Kimberlite... wonder where the big diamonds are? Going to have to keep my eyes open on the beaches, huh? Thanks for the link. food for thought.
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Deleted
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Post by Deleted on Dec 19, 2014 18:36:09 GMT -5
They key to diamonds is the shape, not color. Diamonds are two square pyramids joins at the base. Octahedral, eight sided.
I believe kimberlite contains magnetite. No matter it is highly magnetic.
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Post by mohs on Dec 20, 2014 7:01:36 GMT -5
hopefully Santa will bring you saw Deb but if he just brings rocks in a socks you'll still be of good cheer
Ed
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Post by snowmom on Jan 18, 2015 5:05:19 GMT -5
spent about an hour looking at this again yesterday. there are also all sorts of slivers of silver looking metal. the rock that keeps on giving! tried to get a photo but this camera even with the magnifier just won't go there.
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