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 Post subject: Re: Gemstones from meteorite impact
PostPosted: Thu Apr 25, 2019 5:12 pm 
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Slightly sleepy/milky quartz can provide a confusing appearance in the hand, and it is easy to initially mistake it for something else. Scratch tests can be misleading too if approached incautiously--I've had it happen to me. Nevertheless, the raman does not lie, especially when it's identifying quartz.

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 Post subject: Re: Gemstones from meteorite impact
PostPosted: Thu Apr 25, 2019 9:19 pm 
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Ken Jones wrote:
For me to sit here and convince someone that this is meteoritic material, I'd have to waste your time with a lot of geology and several electronic scan results. .


Here is the general way to identify a meteorite: http://meteorites.wustl.edu/check-list.htm

For your rock, it amounts to this:
https://xkcd.com/1723/


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 Post subject: Re: Gemstones from meteorite impact
PostPosted: Mon Apr 29, 2019 1:29 am 
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Oh my, that was a good one...got a heck of a laugh out of "rock hound turnips".... :lol: :lol:
Please bare with me and I'll do my best to show you some of the things that helped to shape my opinion on this subject matter.
There was a lot of different test equipment bought but most was of little use, the numbers just never seemed to line up. The composition, SG, RI and hardness for most of this material had been altered or modified. Almost all of it is magnetic to some degree and most have metal inclusions. Was told that the metal would make any SG reading invalid.
Here is photos of some of the test equipment used.


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 Post subject: Re: Gemstones from meteorite impact
PostPosted: Mon Apr 29, 2019 3:55 pm 
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I (like many others) don't trust the results from thermal testers. Hardness testers are easily misused. The specific gravity is useful, but only so useful. Certainly not helpful for telling if a rock is meteoric in origin.

The first link I sent you is about as best as you can get for identifying meteoric material.


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 Post subject: Re: Gemstones from meteorite impact
PostPosted: Mon Apr 29, 2019 5:12 pm 
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Hi Ken.

I must ask.

Are you at all open to considering that that you may be wrong?

Are you open to the possibility of user and instrument error?

Are you open to admitting that you might be unqualified to make these assertions?


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 Post subject: Re: Gemstones from meteorite impact
PostPosted: Mon Apr 29, 2019 5:16 pm 
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Which of those instruments/tools did you use on which stones?


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 Post subject: Re: Gemstones from meteorite impact
PostPosted: Wed May 01, 2019 1:41 am 
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-None of this material is a meteorite, it's what's called "impactites".
-Could I be wrong, but of course, I am no scientist but I have had scientist agree that the most likely cause for the high content of metal being found in these stones is a impact event but also agree that more testing and research will have be done to confirm that.
-I wouldn't consider any testing that I did to be very correct at all but it was better than nothing. Of the 2 stones shown only the hardness and SG testing was used.
Below are the edx scan results of five stones, these scans are showing only the composition of metal that is in the stones. The scans were recommended in order to rule out slag.


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 Post subject: Re: Gemstones from meteorite impact
PostPosted: Wed May 01, 2019 11:35 am 
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I am not an expert on meteorites specifically, but I can say that having little bits of various metals isn't an impactite signature. Meteorites are not associated with high concentrations of copper either. I am really curious who is saying this looks like an impactite to them.

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 Post subject: Re: Gemstones from meteorite impact
PostPosted: Thu May 02, 2019 1:06 am 
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Thought this might shed some light:
Quote:
Abstract
Geochemical analysis is an essential tool for the confirmation and study of impact structures and the characterization of the various rock types involved (target rocks, impact breccias, melt rocks, etc.). Concentrations and interelement ratios of the platinum-group elements, as well as the osmium and chromium isotope systems, allow quantification of extraterrestrial components and the identification of impactor types in impact deposits. In addition, chemolithostratigraphy can reveal the possible role of impacts in environmental change throughout the geologic record. This article deals predominantly with terrestrial impact structures.



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 Post subject: Re: Gemstones from meteorite impact
PostPosted: Thu May 02, 2019 12:50 pm 
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Ronald Terik Daly of John Hopkins University wrote:
.Meteoritic signatures in impactites can be discerned in three ways: platinum-group element (PGE) abundances and ratios, osmium isotopes, and chromium isotopes (e.g., Tagle and Hecht, 2006, Goderis et al., 2013, Koeberl, 2014). For many types of meteorites, the osmium isotope technique is the most sensitive ( Koeberl et al., 2012); therefore, this method is well-suited to revealing a hitherto undetected meteoritic signature. However, differentiated achondrite impactors, such as eucritic objects, are difficult to detect with either PGE abundances or osmium isotopes.


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 Post subject: Re: Gemstones from meteorite impact
PostPosted: Sun May 05, 2019 12:45 am 
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--Some of these metals such as copper and lead had me curious too as to how they could be connected to a meteorite but I was told by a scientist to keep in mind that all the metal elements in earth arrived here by meteor impacts.
--Thanks Barbra, lots of great info. Most of the scans we had done were edx but there was one rock that had a xrf scan done and a few of the platinum group elements did show up. Was told that the iridium in this rock was about 8 million times higher than what's found in normal earth soil (see photo below).
--I really appreciate the interest that you all have shown in this subject and I am learning a lot from everything you all have written. While I have your attention, I also have some gemstone stuff that is really, really eating at my curiosity that I would love to get your expert opinion on. Should I start a new post or just keep adding to this one?


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