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.
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. .
Oh my, that was a good one...got a heck of a laugh out of "rock hound turnips".... 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.
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.
-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.
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.
Joined: Sun Oct 16, 2005 12:22 pm Posts: 21602 Location: San Francisco
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.
Joined: Sun Oct 16, 2005 12:22 pm Posts: 21602 Location: San Francisco
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.
--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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