Naked Science Forum

Non Life Sciences => Geology, Palaeontology & Archaeology => Topic started by: austinl on 06/07/2010 22:12:54

Title: Help identifying rock from oregon?
Post by: austinl on 06/07/2010 22:12:54
Found this rock on a trip to Oregon in a river. I polished it after i found it.
http://www.flickr.com/photos/51886910@N08/ (http://www.flickr.com/photos/51886910@N08/)
Title: Help identifying rock from oregon?
Post by: RD on 06/07/2010 22:30:12
Similar to onyx ? ...

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http://www.flickr.com/photos/51886910@N08/                   http://en.wikipedia.org/wiki/Onyx
Title: Help identifying rock from oregon?
Post by: Bass on 07/07/2010 00:04:20
2nd picture (back) looks suspiciously like obsidian (volcanic glass).  If not, then it is some form of cryptocrystalline (extremely fine-grained) quartz- opal, chert, chalcedony, flint, etc.
Title: Help identifying rock from oregon?
Post by: austinl on 07/07/2010 01:19:06
Your saying it could be green obsidian? i found it in the Russian river not near crater lake.
Title: Help identifying rock from oregon?
Post by: frethack on 07/07/2010 14:36:58
Quote from: austinl on 07/07/2010 01:19:06
Your saying it could be green obsidian? i found it in the Russian river not near crater lake.

Rivers carry loads of material depending on the bedrock/sediments that the flow over/through.  This piece obviously hasnt travelled far, or it would be better rounded.  I think Bass is right...it looks like it could be obsidian.
Title: Help identifying rock from oregon?
Post by: Karen W. on 08/07/2010 07:41:33
Quote from: austinl on 06/07/2010 22:12:54
Found this rock on a trip to Oregon in a river. I polished it after i found it.
http://www.flickr.com/photos/51886910@N08/ (http://www.flickr.com/photos/51886910@N08/)
I agree with Bass looks like obsidian to me also... By The way! I love the Russian River... we spent loads of time on that river as kids with my Mom and Grandma...picnicking etc.. It's lovely isn't it?