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Post by vegasjames on Jul 21, 2013 19:44:00 GMT -5
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Deleted
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Post by Deleted on Jul 21, 2013 20:17:46 GMT -5
0.030"?
Nice images! What are they?
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Post by Deleted on Jul 21, 2013 20:24:42 GMT -5
Do you have the resources to do this? If you do can you identify rare earths? I have about a hundred stones that I would like to know what they are. No problem right? lol Just kidding. This setup sounds like it would not be to expensive. I don't think my saw would cut that thin though. Does the stone need to be polished?
Thanks for posting this. Very interesting. Jim
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Post by Deleted on Jul 21, 2013 20:39:50 GMT -5
Jim, the microscope setup for geological work and have the quality for imaging ain't cheap.
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Post by vegasjames on Jul 21, 2013 20:40:38 GMT -5
0.030"? Nice images! What are they? The stone these were taken from is a suspected meteorite. I showed the stone to a meteorite dealer in Coronado, California who was helping me to learn how to identify meteorites. He studied the stone for about 20 minutes under the loupe then exclaimed "this looks Martian". I have researched Martian meteorites and he is correct, but it also has characteristics of other meteorites including angrite structured inclusions. The stone also contains fragments of iron-nickle and zeolites, which have not been found in any Martian meteorites. On the other hand I found in my research that there is some scientists questioning if any of the Martian meteorites we have are actually from Mars. The reason is that the Martian surface is rich in zeolites, which have not been found in any Martian meteorites to date. If from Mars though the presence of iron-nickle would be easy to explain. Mars has been hit numerous times by meteorites which can contain iron-nickle or that be composed completely of iron-nickel. And meteorites commonly fragment and mix on impact with other parent bodies. Because of the gravitational pull of Mars it would require a really serious impact to eject material beyond Mars gravitational pull. Such an impact would definitely fragment a meteorite. The stones and their thin sections also show evidence of intense shock that could occur from a meteorite impact. Some stone shows evidence of shock darkening, which occurs from intense impacts and the thin sections show undulatory and mosaic extinction that also occur with intense shock. Unfortunately I am still awaiting an answer from the lab. The stone has been at the lab for over 6 years now and I cannot get them to tell me much of anything. By the way, don't ask where I found it because you will not get an answer.
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Post by Pat on Jul 21, 2013 20:41:31 GMT -5
Beautiful ! What is the stone?
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Post by Deleted on Jul 21, 2013 20:45:04 GMT -5
By the way, don't ask where I found it because you will not get an answer. Did you find a large deposit of mars in the Mojave desert? Seems to me even if you told me how to find the exact same football field, still nobody would find a thing.
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Post by vegasjames on Jul 21, 2013 20:58:38 GMT -5
Do you have the resources to do this? If you do can you identify rare earths? I have about a hundred stones that I would like to know what they are. No problem right? lol Just kidding. This setup sounds like it would not be to expensive. I don't think my saw would cut that thin though. Does the stone need to be polished? Thanks for posting this. Very interesting. Jim I don't do the thin sections myself. I sent the stone samples off to have them thin sectioned so I can study them since the lab was not telling me much. The this sections cost around $15 each to make. I do have polarizers and microscopes to examine the thin sections. That is how I go the photos. It is the microscopes that take some bucks, especially if you get a polarizing microscope. No, the stone does not need to be polished. Just cut the stone then mark the area for the lab that you want thin sectioned within the size of the slide you choose. I went with a standard slide size, but they do have a larger slide available if you want a larger thin section. The bright green on the first pic is actually from the green permanent marker I used to mark the section of stone I needed thin sectioned. The black line running through the first stone I think is a shock vein. In the 5th photo you can see the two different lithologies of the stone. The white area in the lower right is really interesting under the microscope. It is a mix of white crystals looking like grains of rice (enstatite?) mixed with black elongated (plagioclase?) crystals that look like they have been cooked. This is the area that looks more like an angrite. One known angrite that looks almost identical was formed from the radioactive decay of Al26, which makes me wonder if this is how this was formed and why some of the crystals looked like they had been thoroughly cooked. The greenish, fan-shaped crystal to the far left in the 5th photo is a zeolite. The white long crystals are plagiclase. The rest of the matrix is primarily chromite. Some of the other minerals present include olivine, augite and elemental iron-nickel.
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Post by vegasjames on Jul 21, 2013 21:03:29 GMT -5
By the way, don't ask where I found it because you will not get an answer. Did you find a large deposit of mars in the Mojave desert? Seems to me even if you told me how to find the exact same football field, still nobody would find a thing. I found what appears to be a strewn filed. Don't worry though I did not "poach" it from California. The field has been cleaned out anyway. But the lab was given the information, which at this point is the only people who need to know.
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Post by vegasjames on Jul 21, 2013 21:09:46 GMT -5
Beautiful ! What is the stone? The stone is believed to be a basaltic meteorite. Takes a really nice polish and I agree is a beautiful stone. At least the darker stone. The light gray stone is not as impressive.
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Post by Deleted on Jul 21, 2013 21:53:37 GMT -5
Poach away!
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Post by vegasjames on Jul 21, 2013 22:02:22 GMT -5
Going out to collect tomorrow North of here.
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Post by Deleted on Jul 21, 2013 22:04:32 GMT -5
Nice, I need more time away. I am envious!
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hobbyrobby
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Post by hobbyrobby on May 7, 2019 18:36:05 GMT -5
Are you still waiting for a "reply" from that "lab"? It's been 12 years now. Certainly, this ID must have been confirmed by now. I have a lot of people contacting me to get their "meteorite" identified. I would like to know the name of this lab, so that I won't send these people to that lab, and possibly have the problems that you have encountered.
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Post by vegasjames on May 7, 2019 20:22:45 GMT -5
Are you still waiting for a "reply" from that "lab"? It's been 12 years now. Certainly, this ID must have been confirmed by now. I have a lot of people contacting me to get their "meteorite" identified. I would like to know the name of this lab, so that I won't send these people to that lab, and possibly have the problems that you have encountered. I have to contact them again and see if they ever got results. My email has changed since the last time I talked to them.
It is at the Natural History Museum in England.
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hobbyrobby
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Post by hobbyrobby on May 11, 2019 19:53:58 GMT -5
Back 12 years ago, you may have dealt with Monica Grady when she worked at the Museum of Natural History.
Today, you will want to contact Sara Russell. It has been years since I have dealt with both of these researchers, so they may not remember me.
But speaking about all researchers in general, I have found that if their tests show that a specimen is not a meteorite, they will be very slow to notify the finder.
But if the specimen is found to be a meteorite, they will ALWAYS (very promptly) give the finder a reply.
Nevertheless, thanks for sharing your images of thin-sections. They are very good.
Maybe we can resurrect this thread, and share more images. I have some thin-sections of Nevada (and California) meteorites, if there is any interest.
Here is an example:
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Post by vegasjames on May 11, 2019 20:22:21 GMT -5
Back 12 years ago, you may have dealt with Monica Grady when she worked at the Museum of Natural History.
Today, you will want to contact Sara Russell. It has been years since I have dealt with both of these researchers, so they may not remember me.
But speaking about all researchers in general, I have found that if their tests show that a specimen is not a meteorite, they will be very slow to notify the finder.
But if the specimen is found to be a meteorite, they will ALWAYS (very promptly) give the finder a reply.
Nevertheless, thanks for sharing your images of thin-sections. They are very good.
Maybe we can resurrect this thread, and share more images. I have some thin-sections of Nevada (and California) meteorites, if there is any interest.
Here is an example:
That is not who I was dealing with there. I forgot her name, but she is no longer there. Mainly I talked with Peter Tandy and he was referring it to a Caroline.
Actually they think it is a meteorite as they were trying to get Oxford University to do an oxygen isotope analysis. I read up on this and due to the time and cost involved it is only done on rare, confirmed meteorites to determine origin. That has been the hold up. They do not have the equipment to do the oxygen isotope analysis themselves and Oxford has their own specimens that get priority.
I also have a lot of evidence pointing to it being a meteorite including an eliptical field and an individual oriented piece found several miles away all by itself, orientated plagioclase, what appears to be fusion crust on some pieces, iron nickel inclusions some with sulfide inclusions seen in some meteorites, what appears to be undulatory extinction in the plagioclase crystals and mosaic extinction in the chlorite inclusions and what appears to be a shock vein running through one of the samples.
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hobbyrobby
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Post by hobbyrobby on May 20, 2019 1:00:17 GMT -5
You're right. The "Caroline" you speak of is the Curator, Dr. Caroline Smith. Here is an image of her with Sara Russel at the Museum: www.psrd.hawaii.edu/July09/Meteorites.London.Museum.html Sorry to hear about the "hold up". Sounds like you got caught in a "Catch-22" between Oxford and the museum. I am sure that they would have given your find more attention had it been found in Great Britain. That's why I take my California finds to UCLA (they get more prompt attention, than if I were to go out-of-state to another institution). But based upon your thin-section description, it sounds like there should have been enough evidence for the BMNH to have conclusively determined that it is a meteorite. You mentioned that you have other specimens. Based on my experiences at UCLA, I am convinced that they would give you a definitive answer, and probably even classify it. I have the name and number of the achondrite expert at UCLA, if you wish to pursue this.
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Post by vegasjames on May 20, 2019 3:33:22 GMT -5
You're right. The "Caroline" you speak of is the Curator, Dr. Caroline Smith. Here is an image of her with Sara Russel at the Museum: www.psrd.hawaii.edu/July09/Meteorites.London.Museum.html Sorry to hear about the "hold up". Sounds like you got caught in a "Catch-22" between Oxford and the museum. I am sure that they would have given your find more attention had it been found in Great Britain. That's why I take my California finds to UCLA (they get more prompt attention, than if I were to go out-of-state to another institution). But based upon your thin-section description, it sounds like there should have been enough evidence for the BMNH to have conclusively determined that it is a meteorite. You mentioned that you have other specimens. Based on my experiences at UCLA, I am convinced that they would give you a definitive answer, and probably even classify it. I have the name and number of the achondrite expert at UCLA, if you wish to pursue this. I would like to get a definitive answer but on average it takes at least 2 years to get a meteorite classified. I would hate to start all over.
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steb
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Post by steb on May 20, 2019 4:11:14 GMT -5
One of my jobs in college was making thin sections in the Geology lab. Thin sections are an important part of identifying the minerals in a rock and are also used for a number of other purposes. In my studies, we were interested in the pressure that occurred in the rock post deposition. By analyzing the linear stresses on individual mineral grains it was possible to determine the direction and extent of deformation. When you are trying to determine from a number of various possible scenarios what deformed the rocks, it helps to know what direction the stress came from. To make this work, you need measure the exact orientation of the rock withing the bedrock before removing it from it's surroundings.
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