Meteorite Times Magazine by The Meteorite Exchange, Inc.

Meteorite Times Magazine

Contents Featured Articles Accretion Desk by Martin Horejsi Jim's Fragments by Jim Tobin Micro Visions by John Kashuba Mitch's Universe by Mitch Noda MeteoriteWriting by Michael Kelly

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Gao-Guenie Meteorite(s): Change is a constant in meteorite science. Get ready for more! Martin Horejsi

Gao-Guenie is a fall from March 5, 1960 that once was thought to be two separate falls. The first appearance of Gao in the Meteoritical Bulletin was in 1967 while Guenie showed up in 1980. And then Gao-Guenie landed on the scene in the 1999 Meteoritical, formally changing the situation for all previous Gao and Guenie owners. According to the Meteoritical Bulletin, no. 83: Gao-Guenie, new name With the recent paper by Bourot-Denise et al. (1998), the Meteorite Nomenclature Committee has decided that a new, collective name, Gao-Guenie, will be bestowed upon all meteorites formerly identified as either Gao (Upper Volta) (frequently truncated to Gao) or Guenie. It had been reported that two meteorite showers occurred one month apart in 1960 in the country now known as Burkina Faso. But the new work confirms

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long-held suspicions that the two meteorites are indistinguishable from each other and that there was most likely only one fall (1960 March 5). The confusion about this meteorite has been compounded by the fact that new stones continue to be found ~40 years after the fall and are given arbitrarily one or the other name. Henceforth, the official name for all meteorites from this shower will be Gao-Guenie, with the names Gao (Upper Volta) and Guenie as recognized synonyms.

The other day I was digging through some stored meteorites and discovered my complete individual of Gao-Guenie. I didn’t have it displayed anywhere and had completely forgotten what it looked like. It was a very pleasant surprise because its color and form were better than I recalled. Further, it seemed larger than I remembered. As an H5 chondrite, Gao-Guenie ranks high in the ordinary part of ordinary chondrites. However, the events of the fall of Gao-Guenie include a deafening sound that could be heard up to 100km away when thousands of stones crashed to earth and through a few hen houses as well.

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What makes meteorite collecting exciting to me, as most of you know, is when a particular meteorite lands at the intersection of being a witnessed fall (the older, the better), is scientifically interesting, and involves some aspects of human culture or reaction. Gao-Guenie fits this bill in several ways. Although calling Gao-Guenie a historical fall might be a stretch, it is over 60 years old meaning its age can be noted as a reasonable proportion of a century. As a witnessed fall, almost all boxes are checked. The only uncertainty is the exact time of fall, but a listed "about 1700 hours" is plenty good enough for me. But the win here is a subintersection between culture and science. The cultural aspect is found in the event that two supposedly distinct meteorites became one. I remember when Gao was Gao, and Guenie was Guenie. Yes, they looked much the same, but the price per gram was usually higher for Guenie because there seemed to be less collection material to go around. But honestly, I think most of us had our doubts about their individuality. There were just too many coincidences to ignore.

When collecting meteorites, some flexibility is needed given that science must be able to change. And that includes the materials science is studying. Like dinosaurs, meteorites have changed names, changed classifications, and even fallen out of being actual meteorites. But as scientific instrumentation and space science evolves, meteorites have also changed origin stories, they have changed their importance in particular studies, and they have changed in total known weight. And now that we have actual rock samples returned from an asteroid, and another space mission named Psyche on its way to study a metal rich asteroid named Psyche, expect many more changes in our understanding and interpretation of particular meteorites. The race is now on to match the stones in our collections with the Asteroid Bennu from which

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the OSIRIS-REx mission just delivered an abundance of material. I have full confidence that when the asteroid material is formally studied, there will be many discoveries that directly affect the specimens in our meteorite collections. But on a side note, in celebration of the OSIRIS-REx sample return accomplishment, I am reading the 2019 book The Andromeda Strain Evolution. Until next time….

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Impact Power and the Tiniest Proof James Tobin I did an article for another media outlet a few years ago about one of the most interesting and least understood impact materials found at Barringer Crater better known to the public as Meteor Crater in Arizona.

Let's take a trip back in time to 50,000 years ago and imagine that it is a pleasant morning. The animals many of which have since gone extinct were roaming the central plateau we now call Arizona. Without any warning, there appeared a blinding light that streaked across the sky accompanied by a boiling trail of fire and smoke. Did the animals raise their heads to look we will never know. The source of the light went into the ground and for the briefest of moments, there was nothing. Then a tremendous explosion tore open a hole in the ground and a firestorm roared across the landscape extinguishing all life for perhaps twenty miles. The earth tremor created was felt by all the land animals for maybe a hundred miles. A cloud of superheated material was rising above the newly formed crater and chunks of rock and asteroid were falling

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around the area out for miles. Nothing was alive moments later when the vaporized portion of the iron asteroid began to cool in the air and fall as a rain of trillions of tiny metallic droplets amounting to thousands of tons of the asteroid. Fifty thousand years later there are still trillions of these tiny bits of melted asteroid in the soil around Meteor Crater. They are called iron spheroids and they were seen and ignored for several decades before their true significance as the major remaining mass of the asteroid was realized by Dr. H. H. Nininger. Daniel Barringer saw them in the soil around the crater. His partner Benjamin Tilghman saw them in the soil samples. Others saw the tiny magnetic particles and also took no real notice. However after the volatilization theory was proposed by Forest Ray Moulton, Nininger sought to prove it by finding the remaining mass of the asteroid in the soil around the crater. And he did find that a great amount of the asteroid could even after 50,000 years be accounted for by the tiniest of evidence in the dirt near the crater. Not all the spheroids have survived to the present time. The ones on the outer edges of the fireball where there was oxygen were turned to iron oxide blew away and quickly rusted away. The iron spheroids with little or no nickel have also rusted away over time. The ones that remain are the ones formed where there was no oxygen in the mushroom cloud, and that have a much higher concentration of nickel and cobalt than was in the asteroid body itself. Once the asteroid was a vapor the gloves were off as far as the composition the spheroids could have. All the possible mixtures of the elements in the asteroid formed and fell as tiny droplets. They are called spheroids but they are not all spheres. They are roughly rounded shapes but many are more elongated than spherical. They are lumpy and bumpy and they are tiny. I have worked with them many times over the last thirty or forty years and it is always work done under some kind of magnification with very good tweezers. I found that magnetized needles were a nuisance when sorting the spheroids. You could not drop them where you wanted after they were stuck to the point of the needle. You would have to knock them off with a tap and lose control of where they fell. Using nonmagnetic tweezers works far better though it is a onespheroid at a time process with magnification. Maybe some kind of tiny electromagnet with a switch is something that I should make in the future. Then I could pick up groups at a time and drop them into the place where I want. Let's insert two weeks right here. That is the time it took for me to think about that last statement and then rummage around in my ancient electronic parts to find a soft ferrite rod from an old radio antenna coil. I stripped off the Litz wire that was on it took it to the lab and ground down one end on a diamond lapping disc into a much thinner rod with a flat tip about two millimeters in diameter. I wrapped regular copper wire on the rod and connected a battery for a test. I just put on a small number of turns to try the concept. I had already placed a magnet on one end to see if the other end would pick things up and it did. The ferrite rod should have permeability and coercivity values that would allow it to become magnetized when the coil was energized but lose that magnetism when the current stopped flowing. I could not use a sharpened nail or needle since they would become magnetic after energizing the electromagnet. I needed the core of the electromagnet to be of a material that could not become a permanent magnet. Ferrites come in all kinds. Hard ferrite materials for example are used to make the refrigerator magnets and the magnets in loudspeakers so I was hoping that the ferrite rod I had was of a soft enough variety to not hold magnetism. The images below show the steps of this fun project.

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So now after a test using a magnet on the far end of the ferrite and a poor electromagnet as proof of concept, I went on to make a good coil of about three hundred turns of insulated copper wire. I added a push button switch and attached a battery. It is not very attractive visually but it is iron attractive when I push the switch. Here is an image of the finished electromagnetic tweezers. I don't know what to call it but I suppose that name will work.

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While I am on the topic of magnetism some of the Nininger spheroids are still attracted to each other after roughly eighty years since The Doctor separated them from the sluggets and bits of iron shale which were all collected together in the soil samples. About one out of twenty spheroids will stick to other spheroids and my fine pointed metal tweezers that have themselves never been near a magnet. I have to lightly tap these into the tiny bottles we use in our displays. The majority never had a composition that made holding magnetism possible. Other spheroids were very easily magnetized and have retained that brief magnetic exposure from decades ago for all this time and maybe forever. Back to the iron spheroids themselves. There is a size range for the spheroids and the larger ones are noticeably much bigger than the smallest ones. To weigh them I found it necessary to screen them with my geological sieves get the sample that I wanted and then take a thousand of those and put them on my milligram scale. Nininger's separation is pretty good but there are some larger ones among his smaller

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ones. I took a sizing screen that would catch the few that were too large to be called small and let the rest pass through. I manually counted out ten piles of one hundred to arrive at my thousand to weigh. Simple division was used to determine the average weight of one spheroid. The same thing could be done with the larger spheroids to get their weight. However, I did not have a thousand of the large ones so I am using Nininger's weight as my data point for the large size. I think I had an advantage over Dr. Nininger by having a variety of highly precise scales at my disposal. But then I don't know what he had in the 1930s and 40s. I sold a scale years ago that would have been wonderful for the spheroid weighing work. It was a Mettler that came out of NASA and could weigh in one-hundredths of a milligram. But it was impractical for me as I had no stable base to place it on. The cars passing on the street and the people walking in the house moved the floor and desk enough to drive me insane when trying to get a true weight reading. A milligram scale is sufficient, especially using a sieved sample of one thousand. I should say at this point that I used the large quantity of Nininger-collected spheroids from my collection for this work and not the ones I found long ago when access to the area was permitted. Mine have not been separated and graded by size as the Nininger ones.

Here are seen the large-size iron spheroids on the bottom and the small ones on the top. The dramatic difference is easy to see but a pinhead dwarfs them all they are still tiny.

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I have said that trillions of the spheroids were produced and that is a big number. They told us in high school that math would be something we would need. On TV and movies, they have joked that math would save us at some point in our lives. Two years ago I found myself needing to do some math. I had to be sure that I was safe writing that trillions of metallic spheroids remain in the soil around Meteor Crater today. I have been very conservative actually in these calculations. By reducing greatly the amount that Nininger estimated was still around the crater. He determined his number by collecting a large number of equal-sized samples from the soil in a selected area near Meteor Crater. I recently read an article that greatly increased the amount far above Ninninger's estimates so my numbers for the spheroids may even be much lower than their true abundance. Dr. Nininger had sampled very carefully an area on the northeast of the crater and extracted the spheroids from his soil samples using a magnetic device of his manufacture. He states several different ranges for the tonnage. But while discussing the cobalt enhancement he wrote that 2,000 - 3,000 tons of spheroids were in just the two square miles used in his sampling. I took a middle-range figure of 2,500 tons and used a metric ton which is midway between an American short ton and an Imperial long ton for the unit in my calculations. Though I am pretty sure that Dr. Nininger used a regular American ton in the 1940's.

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The image shown here is one thousand sieved small spheroids. They weigh on average 0.88 milligrams each. Nininger determined the weight of the large ones he used for metallurgical analysis to be 2.778 milligrams each. The average of his large ones and my small ones is 1.829 milligrams. 2,500 metric tons equals 2.540 trillion milligrams and therefore using my average weight. More than 1.3887+ trillion spheroids are remaining in just the two square miles northeast of Meteor Crater. There is an obvious problem of taking the largest and the smallest and doing a straight average. It would be better to take a large number of sieved fractions and determine a truer distribution of the sizes and weights for each fraction of the whole sample. However for my purpose here the average is in this writer's opinion close enough to illustrate the points of interest. That was fun and maybe no one else has done this. I should copyright this info somehow. Actually, it is copyrighted right now. The spheroids as I said before had been seen and mentioned as magnetic particles in the soil around the crater since at least the 1905 work of Barringer and Tilghman. But they were looking for the whole asteroid and not interested in the tiny spheroids they considered to be of no value in the dirt. Tilghman dropped out of the joint endeavor of Standard Iron Company and was bought out by Barringer. Barringer spent the next couple of decades promoting and raising money for the exploration of the crater to find the gigantic mass of nickel-iron he believed was buried there. He began work at Meteor Crater as a man who was very well off financially. He had the mine in Arizona which was one of the largest discoveries of gold and silver ever in the state. By the end, after spending all he had on Meteor Crater he sold his home and property and moved the family into a rental. He managed to still send his sons to Princeton I think, but he was no longer wealthy. Here is what might have happened if he had just pulled a larger number of magnets through the soil around Meteor Crater as he cut the soil with plowing discs. Taking Nininger's tonnage of spheroids in his two-square mile sampling area and cutting his concentration in half to be super extra careful yields 750 tons of spheroids per square mile. Using the often quoted area of 200 square kilometers (78 sq. miles) as the area where condensation and other products of the impact are concentrated. The total weight of spheroids in that whole area around Meteor Crater is even at my reduced level 58,500 tons. Using the enhanced percentages of Nickel and Cobalt Nininger determined were in the spheroids as the composition it is possible to determine the value. The following easily possible numbers result. Remember I am using 1/2 Nininger's concentration of spheroids to be conservative. The elemental analysis that Nininger got has also been confirmed by others since his time. Nickel Amount and Value 10,237.5 tons of Nickel which equals 22,569,792 pounds of Nickel. At the known 1922 price of $0.42 per pound that is $9,479,312.64 that Barringer could have extracted from the area around Meteor Crater as a raw magnetic "ore." Cobalt Amount and Value 731.25 tons of cobalt which equals 1,612,128 pounds of cobalt with a price fixed by producers for years which was in 1937, $1.29 per pound or $2,079,645 give or take a little for any small

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difference in the 1922 price. For a conservative total of over $11,000,000 that's millions with an "m" in 1922. Talk about missing a resource. I have also said nothing about the "FREE" iron that would have been collected along with these more valuable and strategic metals. The iron amounted to around 48,000 tons. That's about the weight of a WWII battleship. The spheroids even the least weathered are surrounded by a coating of iron oxide so whether all the weight would be available to smelt into iron ingots is a reasonable question to ask. Some certainly would have been recovered and with the amount available the smelting process might have been adjustable to permit getting the most material from the spheroids. Especially because there was no rock to be crushed and disposed of. And the slag would have been quite different from that in a regular smelting routine. Barringer and everyone else since the beginning of investigations knew about the spheroids and other nickel-iron particles in the soil. Add to these amounts the thousands of meteorites that would also have been recovered if he just scrapped the soil into some type of collecting machine like a dry washer with magnets he would have been rich. Instead, Barringer spent $150,000 of his money and roughly $600,000 from outside investors looking for something that was not there. His buried star. But it is not all Barringer's fault. Meteor Crater was the first crater to be investigated as a place formed by an asteroid impact. The crater played tricks on him too. His drillings into the floor of the crater hit meteorite fragments in most of the original twenty-eight holes he drilled. He did not realize that those were small fragments that fell into the crater immediately after the explosion and were mixed and covered by fallback rock and lake deposits. The thousands of fragments buried under the crater floor and those found so far along with fragments remaining on the plain surrounding the crater represent only a tiny amount of the original asteroid. But Barringer could not know that or believe that. The presence of all the pieces his drill hit just led him to create new theories that always ended with an assumption that vast amounts of pure nickel-iron were buried at Meteor Crater. Barringer could probably never have conceived at the beginning of the work that the projectile had penetrated many hundreds of feet of rock before coming to rest and exploding. In 1920 Barringer signed a lease with United States Smelting Refining and Mining Co. to drill on the south rim down into the area of greatest uplift and deformation at the crater. Though unsuccessful at reaching the buried mass of nickel-iron because it was never there. The drill did hit masses of meteorite that were extraordinarily hard to drill through. They were as hard as the drill bits and progress was made at the expense of dulled and repeatedly resharpened drill bits with only a single inch of progress made in a whole day sometimes. But the explosion of the asteroid did send pieces of the nickel-iron everywhere even if the final surviving amount was small.

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At the top center of this image of the south wall there is a leveled area where 5000 tons of material was removed to make a platform for the drill rig and building around the derrick. This spot was the center of activity in the early 1920's. The timbers seen in the image are from the rig and the surrounding building which were pushed off into the crater at the end of the work.

I looked for the most recent estimates for the mass of the asteroid that formed Meteor Crater and was not very happy with the results of that internet search. Some references are for several hundred thousand tons. I guess no one wants to try or maybe they can not work it out more closely. Years ago the value was near 150,000 tons. Nininger states at one point 200,000 tons. If we use the 150,000 amount and remember that they are thinking even bigger today then this simple math work will show clearly what happened. The Meteoritical Bulletin currently shows 30 tons for the amount of Canyon Diablo meteorites recovered from around the crater. If there were for example double that amount for all the fragments under the crater floor. And add some more for the fragments not yet found around the crater and further round it up to 100 tons of fragments this is the percentage of what survived the impact. Just 0.000666% of the impact mass. So to put the expression the other way, 99.99933% of the asteroid vaporized. Moulton was certainly right and his 1920 math was indisputable. Did Barringer finally realize that no asteroid metal remained, we won't ever know. But he was disturbed by the report. Within a few days of the release of Moulton's calculations, Daniel Barringer was stuck with a heart attack and died. It is reported that he was highly agitated by the vaporization theory and was scrabbling to try and rally supporters to his stubbornly held conviction that a great mass of asteroid was still buried. So maybe he never gave up his belief after all. Today the iron spheroids from Meteor Crater are fascinating reminders of the power of cosmic impacts and of the immense heat released when something nearly twice the mass of the Queen

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Mary, iron, solid and compact hits the Earth at fantastic speed. Now for the commercial break. We have neat displays of Meteor Crater spheroids collected by H. H. Nininger for sale at Meteorites-For-Sale.com. They will make a wonderful addition to any collection of Meteor Crater meteorites, impactites, and materials.

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Portales Valley H6 John Kashuba Portales Valley H6 is an odd meteorite. Since it fell in New Mexico in June 1998 researchers have worked to explain how it formed. The metal that conspicuously separates angular silicate clasts might have come from the chondrite mass during a large impact. Another source might have contributed metal in a lesser impact if the parent body was still partially molten at the time. A clue might be the varied compositions of the metal. Both metal and silicates show signs of slow cooling. The metal has acquired a Widmanstätten pattern. The mineral grains show only low shock levels, presumably through annealing. Crater fallback material might have insulated the shocked material from heat loss. Or continued accretion onto a young H-chondrite body might have done the same. The formation events mobilized several elements that transformed existing minerals and formed new ones. David Weir’s excellent Portales Valley page provides details from several published studies. Ruzicka and Hutson wrote a well illustrated piece for PSRD which is a summation of the exhaustive work by Ruzicka, Killgore, Mittlefehldt and Fries.

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Two metal-rich slices, a thin section and a centimeter cube.

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Exposed metal "veins" at the top of this slice resemble heavy foil.

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Thin section with bright metal.

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Metal, sulfides and other minerals are opaque to transmitted light. Thin section backlit.

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Thin section viewed in incident light. Metal is white and troilite is rose colored. Field of view is 2.4mm wide.

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Vein of rose colored troilite. FOV = 2.4mm.

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Same view in plane polarized transmitted light.

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Same view in cross-polarized light, XPL.

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This and the following photos are from several thin sections. The few remaining chondrules and chondrule fragments in this metamorphic grade 6 chondrite are mostly barred olivine.

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Mbale, Uganda – Cure from the Heavens Mitch Noda In a CBS news article, it listed Mbale as one of the top five strangest meteorites you can buy. The others were Valera (cow killer), Almahata Sitta (only asteroid/meteorite tracked to Earth), Peekskill (striking a Chevy Malibu car), and Ensisheim (chained up in a church to keep it Earthbound). On 14 August 1992 at around 3:40 pm, a meteorite fell in Mbale, Uganda. There was a deafening explosion which occurred over a densely populated city of Mbale, Uganda. There was a shower of rocks which ranged in size from 0.1 grams to 27.4 kg. Scientists estimated that the original meteor weighed upwards of 2,000 pounds (907 kg). The approximate recovered weight was 108 kg. In one of only two documented cases of a meteorite striking someone, a small meteorite fell through the leaves of a banana tree and hit a young boy on the head. He was not hurt.

23.37 gram Mbale half stone with Ruben Garcia label.

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23.37 Mbale showing the other side with dark fusion crust and several peek a boo views of the matrix.

An expedition was organized by the Dutch Meteor Society, the Leiden Observatory, and Makerere University between August 29 and September 5th, 1992. They located 48 impact positions of masses. Mbale classified it as an ordinary chondrite (L5/6).

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A closer look at the cut side of the L5/6 with a dark impact melt vein running across the meteorite.

In the 1990’s, Uganda was ravaged by AIDS, and there was no cure. The desperate people of Mbale thought their prayers were answered by the cure that rained down from the Heavens. Many of the meteorites were ground up and ingested or applied topically. To put this in perspective, by 1994, AIDS became the leading cause of death for all Americans ages 25 – 44 years old. Not just in Africa, but the entire world was hoping for a miracle cure.

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Another look at the fusion crusted side.

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The cure from the Heavens that was not, for those desperate people of Uganda. References: The Mbale Meteorite Shower - NASA/ADS Mbale - The Meteoritical Society – Meteoritical Bulletin Database Top five strange meteorites you can buy – X-SCITECH – Wynne Parry - CBS News MBale - Christie’s On this day in Space: Aug. 14 (1992): Meteorite Shower Hits Uganda – MSN Origins of Meteorites – Meteorite Collection – UCLA Catalogue of Meteorites (5th Edition) Monica M. Grady, The Natural History Museum 1990s HIV/AIDS Timeline – American Psychological Association National Institute of Allergy and Infectious Diseases

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Tenham The Meteorite That Teaches Us About Our Planet's Mantle Michael Kelly I have to admit I have a soft spot for Australian Meteorites. That fondness stacked on top of my constant search for meteorites that are mineral type localities, and a separate love for meteorites that would qualify under the traditional definition of “antique”, makes Tenham a hattrick type collection piece for me. Tenham fell near Tenham Station, Queensland Australia in 1879. It was a nighttime fireball (somewhere around 2 to 3 A.M.) with several witnesses, but there is no exact date associated with the fall, just a that it was in the first quarter of the calendar year. With an impressive age of 144 years on earth, much of the writing on Tenham is itself vintage from the 30s through the 70s, full of terms mostly out of the vernacular today. The Aerolite shower produced a stone count of around 300, amounting to a total know weight of over 200 kilograms (as reported in Hellyer’s mass distribution study), 160 kilograms listed in the meteoritic bulletin. Many of recovered stones are described as complete or nearly so as recorded by Hellyer having used 250 Tenham meteorites as part of his study. Tenham was classified as a veined olivinehypersthene chondrite, an L6 nowadays. Tenham is a well-studied and referenced meteorite when it comes to shock related research. This is due to it sitting at the end of the shock scale, S6, (though a few studies put it at S5) along with the fact that the preponderance of the fall is curated in a few major institutions. So it is no surprise that the 4 new minerals found in the Tenham meteorite which get it a status as a major type locality collector piece are found within the shock veining. Shock veining is associated with high pressures and temperatures achieved as impact shock pressure passed through the parent body. In the case of Tenham that pressure was between 25 and 45 GPa, shock veining occurred due to shearing throughout the rock due to differential localized shock impedance characteristics (Langenhorst, 95). The type locality minerals of the Tenham meteorite: Akimotoite is a rarely seen member if the ilmenite group with a formula (Mg,Fe)SiO3. It was first discovered by N. Tomioka and K. Fujino in 1997, and published about in 1999 in American Mineralogist. It’s a polymorph of both pyroxene and bridgmanite (also with a type locality of Tenham). Since its formation environment precludes it from forming on the Earth’s surface its other representative examples are in meteorites like Zagami and Umbarger. Of note it is theorized that it is a significant constituent mineral of the Earth’s upper mantle 370-500 miles deep. Bridgmanite is the (Mg,Fe)SiO3 magnesium end member of the Perovskitites group. It is theorized that this is the most prevalent mineral constituent on Earth’s mantle (making up 93% of the deep mantle), thus making it the most abundant mineral on Earth. Since it forms in the deep mantle (420 to 680 miles down) a terrestrial occurrence has yet to be found so meteorites and lab produced sources are all we have. Bridgmanite is a high pressure polymorph of

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enstatite. Though synthetic lab produced material was published about in the 1980s, following the rules of mineral naming however it wasn’t till it was found in natural form in Tenham in 2014 by Chi Ma and Oliver Tschauner, that it was formally allowed to be named. Poirierite like bridgmanite was theorized to exist long before it was found, some 40 years ago by its namesake Jean-Paul Poirier. Poirier’s extensive research focused on the Earth’s mantle and core. This high pressure polymorph of olivine with a formula of Mg2SiO4 wasn’t describe from a natural occurrence till 2021. The final type locality mineral in Tenham might be the most well-known among meteorite collectors, ringwoodite. This is the oldest first ever mineral found in Tenham with an official naming in 1969. Like Poirierite it too was named in honor of the scientist who theorized its existence, Alfred Ringwood, who happened to be a predominant Austrailian geologist and geochemist. It is a high pressure polymorph of the fosterite end member of olivine, but has a spinel structure. It is also a polymorph of Poirierite and Wadsleyite. What helps ringwoodite stand apart from most other minerals found in meteorites is, being a spinel, although it can be grey to colorless, it can also be quite colorful as bright blue to purple grains. Tenham is a meteorite that has been critical to helping us better understand the composition of the depths of our planet. By allowing us access to naturally occurring mineral samples exposed to the pressures and temperatures similar to mantle of our own planet we would otherwise be unable to access. Tenham sat on my wish list for quite a long time. I avoided the pressures to get just a small bit and move along in my collecting. I wanted a nice crusted piece that showed off how well it has held up over nearly a century and a half, and I definitely wanted to have nice shock veining. With a little help from Roberto Vargas while he was at the Denver Show I was put on to the nice 26-gram piece that met all my requirements. Till the next type locality- Mike

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Photo image 5815 (left - before) and photo image 6150 (right - after polished). My 26.118-gram end cut, it came to me at 26.2 grams but being a perfectionist, I wanted the cut face immaculate, a perfectly polished face was well worth the 2 thousandth gram loss.

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Crust still looking black and fresh after 144 years

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Thin section I made out of a small secondary piece, it contained a nice thick shock vein displaying beautiful blue ringwoodite grains.

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Robert’s collection piece, 18.16 grams and a Schwade number, a reminder for me to hold out and get a good one. Thanks for the assist in getting me steered in the right direction buddy!

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A Stone’s Journey: From Space to New Jersey? Roberto Vargas At approximately 12:14 p.m. EDT on Monday, May 8, 2023, a ~1kg stone smashed through the roof of a home in Hopewell Township, Mercer County, New Jersey. No one was home at the time of the event. However, the owners would come home to find a mysterious 984g stone resting near the bed in one of the upstairs bedrooms. Upon examination, they realized that this stone had crashed through their roof, bounced off their hardwood floor, and then impacted the ceiling again before landing in its final resting place. One of the finders would later recount that the stone was warm to the touch when she picked it up. This event made the news, which prompted me to take a drive down to New Jersey from Connecticut. I had just gotten back from an unsuccessful hunt in Elmshorn, Germany, but I couldn't miss this opportunity.

Author with finders.

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When I showed up at the home, I noticed a man standing at the doorway, so I approached and asked if he would be willing to discuss the meteorite that had struck the house three days prior. The man and his wife were reluctant to speak to me at first, stating that they had already been questioned multiple times and that they weren't in possession of the stone, as it had been taken to the local university for study. I spoke to them a bit about some of the meteorite recoveries I had taken part in, and they slowly became less defensive. They were very kind people in a situation that was completely unexpected. I could sense and understand their apprehension. That was when they mentioned that one of the hunters who had been there the previous day had encouraged them to look around for additional fragments. That morning, she had decided to take that hunter's advice and looked under and around the bed. While doing so, she found two additional fragments: a 1.9g crusted fragment and a 13.6g crusted fragment with impact marks from hitting the wood floor.

13.6g fragment found on the morning of May 11th with marks from impact with floorboards.

Meteorite Times Magazine

13.6g fragment found on the morning of May 11th interior.

I would later buy that 13.6g fragment from the owner and worked with another private party to purchase the remainder of the stone. One stipulation of the sale made by the owners was that the majority of the main mass would go to an institution. However, I was able to secure a 90g sample (after donation for classification). The entrance piece of the roof and ceiling, as well as the floorboards, will be used to make a display at the main mass's new home. I was given the opportunity to keep the ricochet impact pit caused by the stone. For your viewing pleasure, I present the most recent U.S. witnessed fall and hammerstone!

Meteorite Times Magazine

101g end-cut next to impact pit from ricochet.

Meteorite Times Magazine

101g end-cut.

Meteorite Times Magazine

101g end-cut.

Before this fall, New Jersey had only one other meteorite on record, "Deal", a 28g OC that fell in 1829. This is New Jersey's second meteorite on record.

Meteorite Times Magazine

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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 © 2010 James Tobin