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Discussion Starter · #1 ·
Hi,

I picked up this rock 'sample' from a landscaping company that couldn't tell me what it was. I would like to know what it is and plan on using more of it in my upcoming 125 gallon African setup.

4 picture links are enclosed of both sides of the piece.

Tanks in advance :thumb:

http://i72.photobucket.com/albums/i161/ ... /Rock1.jpg

http://i72.photobucket.com/albums/i161/ ... /Rock2.jpg

http://i72.photobucket.com/albums/i161/ ... /Rock3.jpg

http://i72.photobucket.com/albums/i161/ ... /Rock4.jpg
 

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Looks like granite to me too. It will be fine
Not sure I see any metal flakes? Shiny particles isn't always metal flakes, it could be quartz, or mica or any number of other things that are safe.
It's gold pyrite and other metal ores that you want to stay away from. That rock will be fine.
 

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Nah thats definetly not granite, we have tons of granite in nova scotia. unfortunatly other then knowing its not granite i have no idea what it actually could be. sorry

Adam
 

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Well there are probably a thousand differnt looks that granite has, not sure you can judge that just by comparing it to the type of granite near you.... I'm sure the granite in Alberta and B.C looks very different from the stuff in N.S....
But I could be wrong... there is a rock "expert" around here somewhere, I forget who, but maybe they'll chime in...?
 

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Looks metamorphic to me from the pics you've posted. Maybe an amphibole gneiss/schist? Can't really tell for sure with pics that small. The glittery mineral grains are likely muscovite - a form or mica, and won't hurt the water. Have closer/higher resolution pics???
 

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Discussion Starter · #9 ·
Thanks for all the replies. I can definitely say the 'flecks' are not metallic. I can post up a bigger picture and try to get closer without it getting blurry, in my next post.

Again, I really appreciate the help with trying to identify it as this was a sample and I'd like to get more of the rock itself.
 

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Discussion Starter · #10 ·

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The shiny 'particles' are muscovite mica crystals. What does the fabric of the rock look like from the broken side? Does it have a 'layered' appearance? Are all of the mineral grains parallel with one another? Can you get a close up shot of the broken side?
 

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Discussion Starter · #12 ·
jcollette3 said:
The shiny 'particles' are muscovite mica crystals. What does the fabric of the rock look like from the broken side? Does it have a 'layered' appearance? Are all of the mineral grains parallel with one another? Can you get a close up shot of the broken side?
I believe I would be correct in saying yes to this question.

Yes, I will be able to get a side view of the rock but can't do so until tomorrow (Sunday) evening as my wife nicked the digicam (off to a baby shower :roll: ) plus the rock is in water at the moment to see if it will affect water parameters - I forgot to do it last night before I went to bed :oops:

Thanks.
 

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This seems to look like pumice rock to me. I have some of it in my front yard. If you run your hand over the top of it and slightly scratch your hand(as if it were very coarse sand paper). I would guess that it may be black pumice.

If it is pumice I don't know if I were to use it. It is fairly sharp.
 

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Sorry it took me so long to reply, but I've been straight out working on some 500 million year old fossil phyllocarids (shrimp-like crustaceans) that are still living, believe it or not. So, the side shot tells much more about the rock than the shots of the top or bottom. This is very definitely a higher grade metamorphic rock. It looks like it is either intermediate between a schist and a gneiss, or a really fine grained unfoliated gneiss. I am leaning toward gneiss, myself. I cant say what the darker minerals are for certain, but amphibole is a very common one. I would call this rock an amphibole muscovite gneiss.

Muscovite will expand slightly with exposure to water, but should be otherwise harmless.

Regards,

Joe
 
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