¹Bhadeshia, H.K.D.H.
International Materials Reviews 65, 1-27 Link to Article [https://doi.org/10.1080/09506608.2018.1560984]
¹Materials Science and Metallurgy, University of Cambridge, Cambridge, United Kingdom

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¹Wilson, J.W.,¹Marsh, L.A.,¹Van Verre, W.,³Rose, M.C.,²Evatt, G.,²Smedley, A.R.D.,¹Peyton, A.J.
Antarctic Science 32, 58-69 Link to Article [DOI: https://doi.org/10.1017/S0954102019000531]
¹School of Electronic and Electrical Engineering, University of Manchester, Manchester, M13 9PL, United Kingdom
²School of Mathematics, University of Manchester, Manchester, M13 9PL, United Kingdom
³British Antarctic Survey, High Cross, Cambridge, CB3 0ET, United Kingdom

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¹Kadoya, S.,²Krissansen-Totton, J.,¹Catling, D.C.
Geochemistry, Geophysics, Geosystems 21, e2019GC008734 Link to Article [https://doi.org/10.1029/2019GC008734]
¹Department of Earth and Space Sciences, Cross-Campus Astrobiology Program, University of Washington, Seattle, WA, United States
²Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA, United States

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¹Jens Barosch,^1,2Dominik C. Hezel,¹Lena Sawatzki,¹Lucia Halbauer,³Yves Marrocchi
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.13476]
¹Department of Geology and Mineralogy, University of Cologne, Zülpicher Str. 49b, 50674 Köln, Germany
²Department of Mineralogy, Natural History Museum, Cromwell Road, London, SW7 5BD UK
³CRPG, CNRS, Université de Lorraine, UMR 7358, Vandoeuvre‐lès‐Nancy, 54501 France
Published by arrangement with John Wiley & Sons

Mineralogically zoned chondrules are a common chondrule type in chondrites. They consist of olivine cores, surrounded by low‐Ca pyroxene rims. By serial sectioning porphyritic chondrules from carbonaceous, ordinary, and enstatite chondrites, we demonstrate that the 2‐D textural appearances of these chondrules largely depend on where they are cut. The same chondrule may appear as a porphyritic pyroxene (PP) chondrule when sectioned through the low‐Ca pyroxene rim, and as a porphyritic olivine‐pyroxene (POP) or porphyritic olivine (PO) chondrule when sectioned close or through its equator. Chondrules previously classified into PP/POP/PO chondrules might therefore not represent different types, but various sections through mineralogically zoned chondrules. Classifying chondrule textures into PP, POP, and PO has therefore no unequivocal genetic meaning, it is merely descriptive. Sectioning effects further introduce a systematic bias when determining mineralogically zoned chondrule fractions from 2‐D sections. We determined correction factors to estimate 3‐D mineralogically zoned chondrule fractions when these have been determined in 2‐D sections: 1.24 for carbonaceous chondrites, 1.29 for ordinary chondrites, and 1.62 for enstatite chondrites. Using these factors then shows that mineralogically zoned chondrules are the dominant chondrule type in chondrites with estimated 3‐D fractions of 92% in CC, 52% in OC, and 46% in EC.

¹Tomoya Obase,¹Daisuke Nakashima,¹Tomoki Nakamura,^2,3Keisuke Nagao
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.13481]
¹Division of Earth and Planetary Materials Science, Graduate School of Science, Tohoku University, Aoba, Sendai, Miyagi, 980‐8578 Japan
²Geochemical Research Center, Graduate School of Science, University of Tokyo, Hongo, Bunkyo, Tokyo, 113‐0033 Japan
³Division of Polar Earth‐System Sciences, Korea Polar Research Institute, 26 Songdomirae‐ro, Yeonsu‐gu, Incheon, 21990 Korea
Published by arrangement with John Wiley & Sons

We measured concentrations and isotopic ratios of noble gases in the Rumuruti (R) chondrite Mount Prestrud (PRE) 95410, a regolith breccia exhibiting dark/light structures. The meteorite contains solar and cosmogenic noble gases. Based on the solar and cosmogenic noble gas compositions, we calculated a heliocentric distance of its parent body, a cosmic‐ray exposure age on the parent body regolith (parent body exposure age), and a cosmic‐ray exposure age in interplanetary space (space exposure age) of the meteorite. Assuming a constant solar wind flux, the estimated heliocentric distance was smaller than 1.4 ± 0.3 au, suggesting inward migration from the asteroid belt regions where the parent body formed. The largest known Mars Trojan 5261 Eureka is a potential parent body of PRE 95410. Alternatively, it is possible that the solar wind flux at the time of the parent body exposure was higher by a factor of 2–3 compared to the lunar regolith exposure. In this case, the estimated heliocentric distance is within the asteroid belt region. The parent body exposure age is longer than 19.1 Ma. This result indicates frequent impact events on the parent body like that recorded for other solar‐gas‐rich meteorites. Assuming single‐stage exposure after an ejection event from the parent body, the space exposure age is 11.0 ± 1.1 Ma, which is close to the peak of ~10 Ma in the exposure age distribution for the solar‐gas‐free R chondrites.

¹G.W. Evatt,¹A.R.D. Smedley,²K.H. Joy,¹L. Hunter,³W.H. Tey,^1,4I.D. Abrahams,⁵L. Gerrish
Geology (in Press) Link to Article [https://doi.org/10.1130/G46733.1]
¹Department of Mathematics, University of Manchester, Manchester M13 9PL, UK
²Department of Earth and Environmental Sciences, University of Manchester, Manchester M13 9PL, UK
³Department of Mathematics, Imperial College London, London SW7 2AZ, UK
⁴Isaac Newton Institute for Mathematical Sciences, University of Cambridge, Cambridge CB3 0EH, UK
⁵British Antarctic Survey, Cambridge CB3 0ET, UK

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^1,2Ju Huang et al. (>10)
Geology (in Press) Link to Article [https://doi.org/10.1130/G47280.1]
¹State Key Laboratory of Geological Processes and Mineral Resources, Planetary Science Institute, School of Earth Sciences, China University of Geosciences, Wuhan, Hubei 430074, China
²Chinese Academy of Sciences (CAS) Center for Excellence in Comparative Planetology, Hefei, Anhui 230026, China

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¹Robert M. Hazen,¹Shaunna M. Morrison
American Mineralogist 105, 627–651 Link to Article [DOI: https://doi.org/10.2138/am-2020-7173]
¹Geophysical Laboratory, Carnegie Institution for Science, Washington, D.C., United States
Copyright: The Mineralogical Society of America

Minerals preserve records of the physical, chemical, and biological histories of their origins and subsequent alteration, and thus provide a vivid narrative of the evolution of Earth and other worlds through billions of years of cosmic history. Mineral properties, including trace and minor elements, ratios of isotopes, solid and fluid inclusions, external morphologies, and other idiosyncratic attributes, represent information that points to specific modes of formation and subsequent environmental histories—information essential to understanding the co-evolving geosphere and biosphere. This perspective suggests an opportunity to amplify the existing system of mineral classification, by which minerals are defined solely on idealized end-member chemical compositions and crystal structures. Here we present the first in a series of contributions to explore a complementary evolutionary system of mineralogy—a classification scheme that links mineral species to their paragenetic modes.
The earliest stage of mineral evolution commenced with the appearance of the first crystals in the universe at >13 Ga and continues today in the expanding, cooling atmospheres of countless evolved stars, which host the high-temperature (T > 1000 K), low-pressure (P < 10-2 atm) condensation of refractory minerals and amorphous phases. Most stardust is thought to originate in three distinct processes in carbon- and/or oxygen-rich mineral-forming stars: (1) condensation in the cooling, expanding atmospheres of asymptotic giant branch stars; (2) during the catastrophic explosions of supernovae, most commonly core collapse (Type II) supernovae; and (3) classical novae explosions, the consequence of runaway fusion reactions at the surface of a binary white dwarf star. Each stellar environment imparts distinctive isotopic and trace element signatures to the micro- and nanoscale stardust grains that are recovered from meteorites and micrometeorites collected on Earth’s surface, by atmospheric sampling, and from asteroids and comets. Although our understanding of the diverse mineral-forming environments of stars is as yet incomplete, we present a preliminary catalog of 41 distinct natural kinds of stellar minerals, representing 22 official International Mineralogical Association (IMA) mineral species, as well as 2 as yet unapproved crystalline phases and 3 kinds of non-crystalline condensed phases not codified by the IMA.