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This boulder is a glacial erratic in New Jersey. Can anyone tell if it's granite or gneiss? When you look at from the side, there appears to be foliation... but when you look at from the top or other angle, you don't see layers and it looks like granite. We're preparing signs for a nature trail and any help would be appreciated! Thanks so much enter image description here

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    $\begingroup$ This is interesting but we need more information. Please read this guide and add in as much information as you can. Also, some top and close-up photos would help. That said, I'm not convinced that it's all one type of rock.... $\endgroup$ – Spencer Sep 1 '18 at 20:53
  • $\begingroup$ The boulder here is located on Garret Mountain in Woodland Park, New Jersey (Piedmont region). However I believe it is a glacial erratic from the Highlands region. The mountain here is basalt. I took some additional photos, with top and other views, which I just added... Many different minerals can be seen. I hope this helps! Thank you very much! $\endgroup$ – V. Lazar Sep 3 '18 at 20:05
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I would call it gneiss because of the foliation. When you look from other directions, you don't see it because you are looking down, more or less, on one layer. You should be able to see some foliation if you look at a cross-section of the layers from another side, but sometimes you get more of a lineation where the crystals align in one direction only.

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