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Featured Monthly Articles Accretion Desk by Martin Horejsi Jim's Fragments by Jim Tobin Meteorite Market Trends by Michael Blood Bob's Findings by Robert Verish IMCA Insights by The IMCA Team Micro Visions by John Kashuba Meteorite Calendar by Anne Black Meteorite of the Month by Editor Tektite of the Month by Editor
Meteorite Times Magazine Lissa: Fell 110 years before Czechoslovakia, and 182 years before the Czech Republic by Martin Horejsi
Lissa is an L6 meteorite that fell in 1808. And thatâ€™s a long time ago by any meteorite collecting measurement. I feel fortunate to have a slice in my collection because Lissa fell when the ancestors on my fatherâ€™s side lived in what was once Bohemia, then Czechoslovakia, and now the Czech Republic.
This crust is so fresh, it doesnâ€™t look a day over two hundred years old.
In general, L6 chondrites are not the most colorful of meteorite matrices, but there are exceptions and Lissa is one of them. But then again, I wonder if the L6 classification might have been a little hasty. There are many visible roundish chondrules with distinct edges. The L seems within reason, but the sixâ€Ś. Five maybe? Four anyone?
As historic meteorites become smaller and ever harder to get, specimens such as Lissa become even more valuable. And not just as meteorites, but as something both physical and conceptual that ties us to the people who centuries before wondered many of the same things we do today about these magical stones from space. Until next timeâ€Ś.
The Accretion Desk welcomes all comments and feedback. firstname.lastname@example.org
Meteorite Times Magazine Mystery Stone Revealed by Jim Tobin I left you all hanging a couple issues ago regarding a meteorite I bought at the Tucson Gem and Mineral Show. Well, I am ready to tell all now that it is done being classified. It was a strange stone, with a very weird looking outside surface. It was a funny color and not very magnetically attractive. Well, it was not very visually attractive either and though the price was sort of normal for today. It was not real bargain wise attractive either.
The whole stone is shown here with a gap a little wider then the actual space of the slice sent for classification. Yet for some reason I thought it could be something interesting if it was truly a meteorite. It was as you can see sort of bubbly on the outside and it had circles that looked just like bubbles with the tops broken away. Here are a couple pictures of the circle and cup formations.
That question of whether or not it was a meteorite remained in my mind as it turned out for two days. I had intended to get a diamond file and grind a spot immediately to see what was inside. It would be a while before Paul and I made it finally to a place where I bought a $2 diamond file. That evening at the hotel room I checked the rock out. I started out a little worried as I ground into it. It was a flat dark gray color inside. I was thinking magnetite for a few seconds then I saw a tiny but unmistakable grain of metal and gave out a sigh of relief. It was undoubtedly a meteorite but it was weird. I placed the 1,500 gram rock in my bag and could not wait to put it in the saw. That happened the following morning after getting home. As I said two months ago I cut off the end piece shown below and almost jumped out of my shoes. It was the most wonderful impact melt I had seen in a long while. Reminded me visually of a Cat Mountain picture I had seen.
I lapped and polished the face of the end piece and hurried into the house. I needed to send this somewhere to get classified. That is not so easy a thing to do in the world today. All the researchers are very busy and backlogged. I took two digital pictures and attached them to an email. I sent it off to my first choice of lab. I was presumptuous enough to say in that email that it was an “impact melt unless I am mistaken”. I guess if I had not been so excited I would have been a little more reserved and let the expert tell me. Especially since I was asking for his help. Dr. Rubin at UCLA has done characterization work on several meteorites for Paul and I over the last 10 years. And I was sure hoping he would be interested in doing this one. I was delighted when I got an answer from him that it was an “impact melted ordinary chondrite”. He wanted to get a normal type specimen size piece and a small piece of each of the two lithologies for making thin sections. So I was off to the saw again and I cut a thick slice off the end piece I had already prepared. I had by pure accident picked a spot on the meteorite that had cracks. So wouldn’t you know, while I was lapping down the thick slice I was giving to UCLA it broke in half. Well, both pieces had both lithologies and both were over the size required for a type specimen so I sent both. Whichever piece was best for thin sections Dr. Rubin could choose. I ran right out to FedEx and sent the pieces off. They weighed a total of 62.57 grams. I was still pretty excited about what a wonderful meteorite the mystery rock had turned out to be. I was seeing Paul the following day and took the stone and end piece for him to see. He had been through all the buying and grinding in the hotel room part it seemed only right to subject him to all my after cutting enthusiasm. The following are the results that Dr. Rubin got characterizing the stone. Work for which I remain very grateful to him. L6 impact melt breccia S6 W2 Fa 24.1 ±0.2 (n=10) Fs 20.4 Wo 1.6 (n=3) Ca-pyx: Fs 8.3 Wo 44.4 (n=2) There are 5-mm-size shocked chondritic clasts embedded in a melt consisting of 2-25-µm-size subhedral silicate phenocrysts and 5-10-µm-size metal-troilite blebs. Also present are elongated troilite veins up top 600 µm in length.
In the following pictures I will try to show some of the features mentioned in the above details.
Here is a shot of the two lithologies of the stone. Chondritic is on the left with a few chondrules showing. The melt material is on the right with lots of round blebs of troilite and metal visible though not illuminated in this picture. The nasty fracture which caused the type sample to break can be seen prominently running up and down.
This shot is of the unpolished face on the main mass. A band of melt is running left to right with chondritic material above and below. It gives a good idea of the tiny size of the 5-10-Âľm metal-troilite blebs in the melt as compared with the more or less normal
size metal grains in the chondritic portions.
In this difficult shot to take, the true small size of some of the blebs of metal in the melt can be seen. The faint lines seen running left to right are 180 grit diamond lap grooves in the unpolished surface. Many of the metal blebs are far smaller then the grooves.
The stone does have larger metal blebs and troilite inclusions in the melt. This is an area that can also be seen in the photo above of the entire polished endpiece face.
Here is an area right at the boundary of the two lithologies where the metal grains and troilite inclusions are essentially normal in appearance for an L chondrite. Once again the tiny metal blebs can be seen in the melt at the bottom of the shot.
I could not help myself and made a thin section of the meteorite. It meant putting the endpiece back in the saw and cutting a slice or two. I had no prior experience with thin section preparation of an impact melt, but it went about like any other thin section. I suppose over the last 15 years I have made almost a hundred thin sections in the garage. I really wanted to be able to give you some pictures of how the meteorite looks on a microscopic level. It took a couple hours for me to make the thin section. It took a couple more to get some nice photos. As one would expect with a type 6 chondrite it will still have chondrules and they will be in poor condition. That was certainly seen here. Aggregations of mineral
grains much of it olivine are scattered in areas that still appear as chondrules to the unaided eye. There were a few chondules that were in a little better shape with the grains of mineral still close together. But. all the chondrules are faded into the ground mass and rimless. Few of the individual crystal grains had distinct sharp edges. There was one very strange structure. I think that it is likely a ruptured chondrule as well. I will start with that picture.
When viewing thin sections in cross polarized light it is important to always rotate the slide so that you not only see everything, but so that you can observe what is happening to the elements you are looking at. Some items may not show at all at a particular orientation of the slide. When rotated some will appear and others will disappear. This disappearance is called extinction. At a certain point in the rotation of the crystal grain it may have its transmitted light cut off by the filters. In fact the angles at which extinction occurs is a measurement taken by optical petrologist when examining rocks and their minerals. So here is another picture of the choundrule shown above but with a large portion not extinguished. I like the extra information seen in the larger first picture. Not only did individual grains appear but interference colors emerged in much of the portion that did not extinguish.
The following picture is of one of the wide aggregations of mostly olivine crystals. The center of the shot shows grains probably all from the same slightly dispersed chondrule.
Here are a few more chondrules that I shot to give a further idea of how different they are from the beautiful sharply defined chondrules of a type three chondrite. For those of you who love crisp sharp chondrules. You will find little in the following pictures to make you happy.
This was once a pretty barred chondrule I think, but not anymore.
This has to be the least exciting chondrule I have ever seen. Normally, I would not even bother to photograph it. When the meteorite has so much recrystallizing showing this is what you get. The next group of pictures show the range of interference colors that olivine often has in cross polarized light. In most cases it is of small masses of crystal grains or portions of disrupted chondrules.
Here is a detail from the picture two above showing how damaged the crystals are in highly shocked meteorites. Though a portion of this meteorite was completely melted and has nothing showing in the thin section but a few widely scattered tiny crystal fragments, the chondrite portion has been pounded badly also. It is too bad that I am not set up to rotate the slide. I would love to check for undulatory extinction in some of these larger olivine masses. Maybe I will have to make a rotating stage for my microscope. The meteorite has been submitted to the Nomenclature Committee and I expect that sometime in the future it will get an NWA number and be included in the official list of meteorites. This is especially exciting for me since this meteorite is unusual and of more interest to science then some others I have had characterized. It does make me wonder about what is hiding inside the other unclassified stones in my collection. Ones I have not cut. This one was just so darn strange and odd looking I had to see inside.
collection. Ones I have not cut. This one was just so darn strange and odd looking I had to see inside. Until next month enjoy your meteorites, Jim
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Meteorite Times Magazine IMCA Insights – April 2012 by IMCA TEAM
IMCA Insights – April 2012 Sikhote-Alin meteorite stolen from the Museum of the University of NewMexico by Anne Black, Dr. Carl Agee, Tim Heitz The story begins with Dr. Carl Agee, Director of the Institute of Meteoritics, and Curator of the Meteorites Collection housed in the Museum, on the campus of the University of New Mexico in Albuquerque:
Meteorite Museum of the University of New Mexico. Front: the main mass of Norton County and Navajo (with a large crack), hanging from the ceiling, a cast. In the back, the empty case of the Sikhote-A lin. (Photo by Dr. Carl A gee)
One of our nicer display specimens in the Meteorite Museum at the University of New Mexico is the 9490 gram Sikhote-Alin. It was stolen from its display case, during public opening hours, sometime before Christmas break 2011 -- the exact day of the theft is still unknown to me. But I did discover that the meteorite was missing on New Year’s Day 2012, when I was giving Michael Farmer a private tour of the Meteorite Museum. The University was closed and the building had been locked up since before Christmas, but I came to campus that day, to meet Michael who had come from Arizona to show me some specimens of the new Martian fall, Tissint. After picking out some choice pieces of Tissint for the museum collection, I then offered Michael a tour of the museum on his way out. As I was showing him the museum displays, moving from case-to-case, I came upon a display where the Sikhote-Alin should have been – but it was empty, not even the label was there, the specimen stand was tipped over. In disbelief, I tried to imagine that perhaps one of our staff had removed it for research or perhaps to clean the display case. After checking with everyone, I sadly came to the conclusion that our valuable meteorite had been stolen. To make a long story short, we contacted the UNM police, they took fingerprints, and eventually we all went home. That evening I contacted Anne Black, Vice President of IMCA, and she immediately offered to distribute an archival photo of our Sikhote-Alin with a report of its theft on the Internet. Then I went to bed.
Early in the evening of January 1, 2012, I received this email from Carl Agee:
"One of our museum display specimens was stolen out of its case -- most likely just before Christmas break, during opening hours. The case has a security alarm, but apparently the theft was not recorded as an alarm by UNM police. I discovered that the specimen was missing this morning when I was doing an inspection of the Meteorite Museum. The specimen is a "Sikhote-Alin" weighing 9490 grams -- see attached photo. I would like to alert the meteorite collector community to be on the look-out for this specimen, it is unique and easily identifiable as our property. What do you think would be the best way to inform those who could help us recover our specimen if it is offered for sale? Thanks, Carl Agee" I promptly responded and told Carl that I would immediately tell everybody, and I sent the following email to MeteoriteCentral, the IMCA mailing list, Club Space Rock, the French Forum and others promptly copied it to other forums they knew (Thanks everybody!), and of course I emailed Meteorite Exchange: "Hello everybody, I am sorry but I do have bad news to start the New Year. I just received the email below from Carl Agee from the University of New Mexico in Albuquerque. A 9490 grams Sikhote-Alin was stolen from their Museum right around Christmas time. Please look at the picture (attached). www.impactika.com/sa-9490.jpg And please do watch for it, it could re-appear during the Tucson Show. Thank you very much for your help. Anne Black" Paul Harris was quick and published a "wanted poster" with picture everywhere, Facebook, RSS Feeds, Twitter, and his many sites www.meteorite.com/missing_stolen.html www.meteorite.com/news/index.htm www.meteorite-information.com www.meteorite-times.com/whats-new www.meteorite-exchange.com/listing/sikhote-alin-meteorite-stolen-from-unm
Photo by Dr. A gee, as posted by Paul Harris
Then very very late that same evening I received an email and another picture from Michael Johnson with the comment "Does this look similar?". Yes, it did look like the same Sikhote-Alin, but as I immediately told Michael I would send the picture to Carl Agee and let him make the identification, and early the next morning he did: "Hi Anne, Incredible! This almost certainly is our specimen. What next? Who has it? Thanks, Carl" When I called him a little later he told me: When I looked at my email inbox in the morning I saw several emails from Michael Farmer and Michael Johnson, sent in the middle of the night, basically saying that they had information about the whereabouts of our Sikhote-Alin. Michael Johnson recognized the photo that Michael Farmer had posted on his Facebook page as the same Sikhote-Alin Tim Heitz had asked him about, concerning the value of the same sample, over the Christmas holidays. I then contacted the UNM police that morning, and they contacted Tim Heitz. Then Carl added that the thief who had sold the Sikhote-Alin to Tim Heitz had bragged that he had more; consequently the Police Department was suspecting that the thief would try to come back and steal another one, and they had asked that the whole matter be kept very quiet so the thief would not accidentally hear that he had been found out.
The story now moves to St Louis and Tim Heitz: On December 21th I received a phone call from a man saying he had a meteorite and wanted to sell it. I receive calls like this all the time. The next thing I usually do is ask that they send me a picture, the picture he did send wasnâ€™t too clear, but it did look like a meteorite. I told him to mail the meteorite to me and if it was a meteorite, I would then buy it from him. I had him mail it to me like I have had dozens of other people do in the past.
Photo sent to Tim Heitz by the person who stole the Sikhote-A lin
On Saturday December 24th I received I found the box on my porch step with a big hole on the side of the box, it was a wonder it made it there. The hole in the box was so big you could put both hands inside the box with no problem, the meteorite was there, and it was a meteorite, so I went to WalMart and wired a money gram for $1,800 to him. The next day I took a picture of it and sent it to a man I thought was an expert with this kind type of meteorite, I really was shocked to find out what he thought it was worth. Then, on Monday morning, January 2, my wife woke me up to tell me a detective from the New Mexico University called and said that I may have a stolen meteorite in my possession. When I called the detective back and when he told me what kind of meteorite it was, I told him that Yes I had it and I thought it didn't seem quite right paying such a low price for it but the man who sold it to me had told me that he knew it was worth a lot more but he needed the money for Christmas presents for his kids and wife. He stated that it belonged to his father who was a rock collector who had died a couple of months prior and it was part of his rock collection. Then I had gotten in touch with Carl Agee of the Institute of Meteoritics at University of New Mexico where the meteorite had been stolen from. He told me he was sending someone to St. Louis to pick the meteorite up. So, on Thursday December 29 at 7:00 p.m. I met Lee Ann and her friend who had just arrived in St. Louis from the Institute of Meteoritics and I gave her the stolen meteorite. We talked for 2 hours about meteorites and as gift to compensate for my loss she gave me a 45 gram piece of Norton County. The Norton County meteorite is a rare type of meteorite, it is a witness fall and there is a wonderful story about how the University of New Mexico's ownership of Norton County came about. It was great to have such a rare and great piece of history added to my collection.
Lee A nn Lloyd and Tim Heitz (Photo provided by Tim Heitz)
And the story concludes where it started, in Albuquerque, with a much happier Carl Agee: Tim Heitz confirmed that he was in possession of the UNM Sikhote-Alin and would hold it safe for us. Over the next few days we discussed how the return of the specimen would be arranged and finally I decided that we would not risk having it sent by mail and so our administrative assistant Lee Ann Lloyd volunteered to fly to St. Louis to take possession of the Sikhote-Alin from Tim Heitz in person and bring it back to Institute of Meteoritics -- which she did on Friday, January 6. The outcome of this theft was incredibly good, and I am extremely grateful to everyone who helped in the recovery effort. My deepest thanks to everyone involved, especially to the quick, decisive action, on New Yearâ€™s Day, by Anne Black, Michael Farmer and Michael Johnson. The epilogue is that a few weeks ago a local TV-news reporter showed up at the Institute of Meteoritics telling us University of New Mexico police had finally tracked down and arrested the person who stole our Sikhote-Alin. He was caught in the act of another campus burglary, and the police quickly realized that they already had an outstanding warrant for his arrest for the IOM meteorite theft!
Dr. Carl A gee and his recovered Sikhote-A lin (Photo provided by Dr. A gee)
This article has been edited by Anne Black and Norbert Classen. • IMCA Home Page • IMCA Code of Ethics • IMCA Member List • Join IMCA • IMCA Meteorite Info
Meteorite Times Magazine NWA 6007 L3.5 by John Kashuba NWA 6007 is terrestrially fresh but shocked. It has well defined chondrules as you would expect of an L3.5. Compression has caused an orientation of components within the stone. Dark inclusions are scattered throughout.
Slice of NWA 6007 L3.5 S4, W1, 28 mm wide. Note orientation of elements.
Fanned sets of olivine bars within a larger chondrule. NWA 6007 L3.5
A porphyritic olivine chondrule (center) and a radial pyroxene chondrule (right center). Both have been squashed and the latter is â€œbleachedâ€?. Water has affected the outer part by
dissolving the glass from between the thin pyroxene fibers. NWA 6007 L3.5
In the center is a cryptocrystalline chondrule. This bright exposure shows it is composed of numerous zones, each of which is a bundle of pyroxene fibers, rather like those in radial pyroxene chondrules but finer. NWA 6007 L3.5
A dark inclusion about 3 mm long. NWA 6007 L3.5
A distorted radial pyroxene chondrule. NWA 6007 L3.5
A fine grained aggregate of minerals among more coarse neighbors. NWA 6007 L3.5
A closer view of the fine grained aggregate. The dark oval is a bleb of metal. Field of view is 1.3 mm wide. NWA 6007 L3.5
In the center, is that an alien handprint?
Skeletal olivine laths grew from right to left. Crystallization was fast and might have been initiated at the right by contact with a cold object. Chondrule is 0.7 mm long. NWA 6007 L3.5
Meteorite Times Magazine Meteorite Calendar â€“ April 2012 by Anne Black Please click on the meteorite calendar to view a larger image.
Meteorite Times Magazine Springwater Pallasite by Editor Our Meteorite of the Month is kindly provided by Tucson Meteorites who hosts The Meteorite Picture of the Day.
Contributed by Robert Ward, Springwater 312 gram slice. Pallasite PMG-an Submit Pictures to Meteorite Pictures of the Day
Meteorite Times Magazine Collapsed Lei Gong Mo Bubble Fragment by Norm Lehrman A collapsed Lei Gong Mo bubble fragment, Guangdong Province, China (from the author’s private collection)
This is a popped bubble where a flap of the skin folded in on itself while still sufficiently hot and plastic to fuse along the inner surface. Both surfaces have seen the same duration of terrestrial etching, but only the original exterior is pitted, suggesting that the skin pitting formed in the first minute or two of the tektite’s existence and didn’t change much thereafter. The technical message regarding skin ornamentation is the same as that told by the classic Nininger “stretch” specimens. However, there is a bit of a paradox lurking here: how did a skin flap a few millimeters thick remain sufficiently fluid to fold and weld while the centimeter thick bubble wall broke in a brittle fashion? A couple
of possibilities occur to me. The bubble might have broken in two stages: first a blister erupted and popped, with a flap folding in and welding to the interior of the bubble, followed sometime later, perhaps on impact, by the shattering of the thicker shell. Another idea for consideration invokes the sill-putty-like character of highly siliceous melts. In volcanic eruptions involving rhyolitic magmas, we typically see that expanding bubbles actually shatter the liquid. These fragments remain sufficiently hot and fluid to weld once they degas and come to rest. The product is a welded ash flow or ignimbrite. Think back to the silly putty of your childhood. Strike it with a hammer and it shatters, but the fragments then slump and flow back into viscous liquid puddles. Might it be that this tektite reflects a bubble that was expanding faster than the glass shell could stretch? A thin flap had enough flexibility to fold and weld, while thicker parts were too stiff to respond at a similar rate. These thick parts cooled and â€œfrozeâ€? before they could exhibit the character of viscous flow seen in the thinner parts. This is counter-intuitive to what one would expect, but grab your silly putty and stretch it til a fine ribbon snaps. The ribbon will elastically rebound and collapse while the thicker parts will (temporarily) hold their form.
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Once a few decades ago this opening was a framed window in the wall of H. H. Nininger's Home and Museum building. From this window he must have many times pondered the mysteries of Meteor Crater seen in the distance. Photo by ÂŠ 2010 James Tobin