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Post by Bob on Sept 14, 2020 23:37:30 GMT -5
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Post by hummingbirdstones on Sept 15, 2020 8:48:47 GMT -5
Beautiful job on those. Would love to see a picture of them in daylight.
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,154
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Post by jamesp on Sept 15, 2020 9:24:14 GMT -5
Well done ! Impressive tumble Bob.
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Post by orrum on Sept 16, 2020 9:22:54 GMT -5
Likee likee!!!
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Post by Bob on Sept 18, 2020 0:08:26 GMT -5
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Post by parfive on Sept 18, 2020 1:02:11 GMT -5
If that's the way we are supposed to always photo rocks, please let me know. No such animal, Bob. Take the pics however it suits ya . . . or your eye. Always appreciated when they’re in focus, though, and you don’t post ten or twenty pics at 5mb apiece. : )
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Post by hummingbirdstones on Sept 18, 2020 9:58:36 GMT -5
Thanks for the pics in sun. I just wanted to see that tiger glow without the light bulb reflections.
You can take pictures in whatever light you like. No rules on that. That was just me asking.
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Post by Bob on Sept 18, 2020 11:31:25 GMT -5
What funny is only after looking at the photo in the sun and of that one side, did I realize there is apparently a quartz layer. Didn't know that could happen in tiger eye.
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Post by Bob on Oct 7, 2020 10:43:24 GMT -5
Here's my attempt to classify this material, which is gold Tiger's eye.
Type: Metamorphic rock Subtype: Tiger's eye Subtype: Color gold = Gold Tiger's Eye, a named rock.
Found particularly in S Africa and E Asia. Mohs 6.5-7.0.
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Post by stephan on Oct 10, 2020 21:25:24 GMT -5
It’s more of a pseudomorph: silica after asbestos, than metamorphic. The original crocidolite (asbestos) was metamorphic, though. I suppose, technically, a pseudomorph is a changed rock, so a second metamorphosis, but I usually see the two terms used differently. Since silica has replaced the original asbestos, the quartz layer isn’t too surprising. Very nice pieces.
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Post by Bob on Oct 13, 2020 16:04:57 GMT -5
stephan, when I was typing the rocks commonly used in tumbling, I categorized in my notes as follows. Granted this was solely for my own use in trying to make sense or the morass of information that hammers a non-petrologist like me.
A = Artificial (Man-made) IR = Igneous Rock L = Mineraloid M = Mineral G = Mineral Group MR = Metamorphic Rock OI = Organic Inorganic composite O = Organic SR = Sendimentary Rock Unk = Unknown V= Variety name (of mineral) X = there is disagreement (such as whether Chalcedony is a mineral or a rock (due to being an aggregate of Quartz and Moganite)).
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pizzano
Cave Dweller
Member since February 2018
Posts: 1,390
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Post by pizzano on Oct 13, 2020 17:14:57 GMT -5
stephan, when I was typing the rocks commonly used in tumbling, I categorized in my notes as follows. Granted this was solely for my own use in trying to make sense or the morass of information that hammers a non- petrologist like me. A = Artificial (Man-made) IR = Igneous Rock L = Mineraloid M = Mineral G = Mineral Group MR = Metamorphic Rock OI = Organic Inorganic composite O = Organic SR = Sendimentary Rock Unk = Unknown V= Variety name (of mineral) X = there is disagreement (such as whether Chalcedony is a mineral or a rock (due to being an aggregate of Quartz and Moganite)). Coming from an understanding developed by association with Geotechnical Engineering.......... more often than not, as I understand within the industry, Petrology deals with rocks original formation, transformation, origin and a bit of structural analysis.......Where-as, in the case of the overall (genetic) identification and description for personal ease of categorization, it appears Mineralogy (Mineralogist) better suits the exhibited "morass" of complimented categorizations.........Just an educated observation.!
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Post by Bob on Oct 14, 2020 10:40:29 GMT -5
piazzao, a former client of mine is the former Head of the Geology Department of a large university, and another is a hydrogeologist of major standing. We have had meals together, and I've heard the various contexts in which geology, mineralogy, petrology, and geochemistry have been uttered between the two of them talking to each other, but I found the way they were used very confusing at times, especially with the two you mentioned. In any field of course, there are the technical and precise uses of the nomenclature, and then there are the general and sometimes sloppy uses of the same terms to communicate with laypeople (i.e. silicates). However, I tend to enjoy hearing people use terms in their correct ways, even if I have to look up and study a bit to understand, so I try to do the same and not accidentally mislead.
Given what you were kind enough to explain, I have looked into the points you mentioned and I believe you that mineralogy is closer to what we are dealing with here, or rather the postings which I've made, than petrology. Thanks you so much for educating me about this and I'll stop using petrology given the reasons you explained and use mineralogy instead. You epitomize the person who gently and respectfully educates others, and you cared enough and were perceptive enough to sense I'm the kind of person who wants to communicate truthfully and accurately. I'm indebted to you!
By using a forum feature called "Participated" threads, I found all the things I had written and searched for petrology. I replaced all instances with mineralogy.
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Jahic
starting to spend too much on rocks
Member since September 2020
Posts: 139
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Post by Jahic on Oct 14, 2020 13:50:42 GMT -5
I’ve never thought to tumble such large pieces. I want to try this!
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Post by Bob on Oct 14, 2020 15:11:54 GMT -5
Jahic, FYI, I tumble a lot of large rocks and plan on posting maybe 10-20 threads about various ones including photos and comments about what went right and what went wrong. I have learned a lot by trial and error. Been real busy lately and have not had a chance to post much. But wanted you to know over the next few months I will post more examples that will give you some guidance.
What happened is I checked to see if large tumbled rocks were being sold on eBay and Amazon or anywhere else. Virtually none were! And it was funny how any listing for "large" tumbled stones meant anything as small as 1" or slightly larger. This was ridiculous to me. So at rock shops I would occasionally ask about if anyone tumbled large rocks and I would say "lemon size or larger". People would look at me like I was crazy for asking.
So...I just decided to find out what would happen by doing it. And, the results are a lot of fun. Now when I go into the field or explore rock shops for things to tumble, I seldom look at anything smaller than lemon size and sometimes not smaller than apple size.
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