all this has been fascinating....and, in pursuit of the phase diagram of water I came across the site 'from ice to water' = it (a Physics course at U. Stony Brook), with a neat historical perspective on water/ice (= major scientists = to include Faraday, Kelvin, one of the Thomson brothers, etc.) Winton http://mini.physics.sunysb.edu/~marivi/TEACHING-OLD/PHY313/doku.php?id=lectures:6 From ice to water [PHY313]<http://mini.physics.sunysb.edu/~marivi/TEACHING-OLD/PHY313/doku.php?id=lectures:6> Until 1950 the idea that pressure melting was the main reason why ice is so slippery was commonly accepted. Surprisingly, in 1850 Michael Faraday had an intuition about what would be the physical reason behind the frictionless ice surface. It was not until 1949 that the theory put forward by Michael Faraday in 1850 was accepted as correct. mini.physics.sunysb.edu ________________________________ From: Fred Marton via MSA-talk <msa-talk@minlists.org> Sent: Wednesday, March 3, 2021 8:55 AM To: Sébastien Merkel <sebastien.merkel@univ-lille.fr> Cc: msa-talk@minlists.org <msa-talk@minlists.org> Subject: [MSA-talk] Re: [EXT] Re: Classroom demonstration of decompression melting? When I was watching one of the videos that Sebastian uploaded to YouTube, one the the suggested videos to the right was this from Matt McCluskey's lab at Washington State University, showing the melting of ice VI in a moissanite-anvil cell. McCluskey's video page (https://labs.wsu.edu/mccluskey/videos/<https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Flabs.wsu.edu%2Fmccluskey%2Fvideos%2F&data=04%7C01%7Cwinton-cornell%40utulsa.edu%7C8e8ac916d8244424905b08d8de5c2138%7Cd4ff013c62b74167924f5bd93e8202d3%7C0%7C1%7C637503834584391074%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=K1254%2Fdu8YVMSZTJ9SVyGTUBmYc%2Fh4K%2Fh5%2F2J3jVv7g%3D&reserved=0>), which has the video embedded in it, has this description: Using a moissanite-anvil cell, pressure is applied at room temperature to freeze water. The pressure is 10 kbar (10,000 atmospheres – over 70 tons per square inch). The diameter of the hole is 0.6 mm. Water becoming ice VI. The ice begins to form on the outer ring of the sample and progresses towards the center. The entire sample is converted to ice VI in less than a second. The ruby chip, used for pressure calibration, is visible in the upper left of the sample. Ice VI becoming water. After the pressure is slowly released, the ice cracks and the phase change begins. The pressure continues to drop inside the gasket. The ice breaks up into smaller pieces that coalesce into larger ones, but the total mass of the ice gets smaller. Eventually only liquid water remains. On Wed, Mar 3, 2021 at 9:45 AM Fred Marton <fmarton@bergen.edu<mailto:fmarton@bergen.edu>> wrote: Thanks for uploading these (and for the original links). The info about the pressure conditions in the description are nice to have, too. Fred On Wed, Mar 3, 2021 at 9:37 AM Sébastien Merkel via MSA-talk <msa-talk@minlists.org<mailto:msa-talk@minlists.org>> wrote: Hello all, The ice VI videos were quite successful! They were downloaded 300 times. We talked with Yagi-sensei and he agreed to have them on youtube. I uploaded them yesterday so everyone can find them easily: - https://www.youtube.com/watch?v=pGuYHmbkkZw<https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DpGuYHmbkkZw&data=04%7C01%7Cwinton-cornell%40utulsa.edu%7C8e8ac916d8244424905b08d8de5c2138%7Cd4ff013c62b74167924f5bd93e8202d3%7C0%7C1%7C637503834584391074%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=kLRurtkx2bg2CEee6eHNE2jjcWdTuueumhF6AtESiH8%3D&reserved=0> - https://www.youtube.com/watch?v=dER6E2cb-y4<https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DdER6E2cb-y4&data=04%7C01%7Cwinton-cornell%40utulsa.edu%7C8e8ac916d8244424905b08d8de5c2138%7Cd4ff013c62b74167924f5bd93e8202d3%7C0%7C1%7C637503834584401070%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=mfqGked9jusUjIIg9s1yf59pzzNicVo51DAZ2teCxjg%3D&reserved=0> Best, -- Sébastien Merkel UMET - Unité Matériaux et Transformations Université de Lille - CNRS http://merkel.texture.rocks/<https://nam04.safelinks.protection.outlook.com/?url=http%3A%2F%2Fmerkel.texture.rocks%2F&data=04%7C01%7Cwinton-cornell%40utulsa.edu%7C8e8ac916d8244424905b08d8de5c2138%7Cd4ff013c62b74167924f5bd93e8202d3%7C0%7C1%7C637503834584401070%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=9KgrLHA8pslSQV%2BalLxX3m1j37RHk9%2FfgLTZ6nFbstQ%3D&reserved=0> Tel: +33 (0)3 20 43 65 16 E-mail: sebastien.merkel@univ-lille.fr<mailto:sebastien.merkel@univ-lille.fr> Le 26/02/2021 à 09:41, Christian Schmidt a écrit : > Thank you for the videos! I agree, nucleating and melting ice VI is a > great classroom experiment. One can demonstrate that ice VI is denser > than the liquid simply by focusing on the culet of the upper anvil, and > letting a single ice VI crystal grow from the bottom upward. We used to > show this to the public in pre-covid times. > Making a good video of this is much harder. > > Christian > > Christian Schmidt > GFZ German Research Center for Geosciences > Section 3.6 Chemistry and Physics of Earth Materials > Telegrafenberg D324 > 14473 Potsdam > Germany > > Tel. (office)+49 (331) 288-1406 > Tel. (lab)+49 (331) 288-1850 or -1478 or -1499 > Fax +49 (331) 288-1402 > E-mailChristian.Schmidt@gfz-potsdam.de<mailto:E-mailChristian.Schmidt@gfz-potsdam.de> > <mailto:Christian.Schmidt@gfz-potsdam.de<mailto:Christian.Schmidt@gfz-potsdam.de>> > >> On Feb 24, 2021, at 10:02 PM, Kurt Leinenweber via MSA-talk >> <msa-talk@minlists.org<mailto:msa-talk@minlists.org> <mailto:msa-talk@minlists.org<mailto:msa-talk@minlists.org>>> wrote: >> >> Yeah, for Pete's sake, please acknowledge the source of that great >> video. I see it without acknowledgment all the time. Perhaps people >> don't know where the video came from. Yagi-sensei also told me that >> the making the crystal sink was very difficult. I made a bad joke >> when I watched it with him in 1990 and said, "Oh, the camera was >> turned upside-down!" I don't think he liked the joke. But, the >> monoclinic shape of the crystal is unmistakeable and so I think the >> film is authentic. Thanks for listening! >> >> - Kurt >> >> -----Original Message----- >> From: Sébastien Merkel <sebastien.merkel@univ-lille.fr<mailto:sebastien.merkel@univ-lille.fr> >> <mailto:sebastien.merkel@univ-lille.fr<mailto:sebastien.merkel@univ-lille.fr>>> >> Sent: Wednesday, February 24, 2021 2:00 PM >> To: Kurt Leinenweber <KURTL@asu.edu<mailto:KURTL@asu.edu> <mailto:KURTL@asu.edu<mailto:KURTL@asu.edu>>>; Robert >> Bodnar <rjb@vt.edu<mailto:rjb@vt.edu> <mailto:rjb@vt.edu<mailto:rjb@vt.edu>>>; Fred Marton >> <fmarton@bergen.edu<mailto:fmarton@bergen.edu> <mailto:fmarton@bergen.edu<mailto:fmarton@bergen.edu>>>; >> msa-talk@minlists.org<mailto:msa-talk@minlists.org> <mailto:msa-talk@minlists.org<mailto:msa-talk@minlists.org>>; John Brady >> <jbrady@smith.edu<mailto:jbrady@smith.edu> <mailto:jbrady@smith.edu<mailto:jbrady@smith.edu>>> >> Subject: Re: [MSA-talk] Re: [EXT] Re: Classroom demonstration of >> decompression melting? >> >> >> Hi, >> >> Here are the videos from Yagi's lab at ISSP: >> https://urldefense.com/v3/__https://filesender.renater.fr/?s=download&token=bb336d91-7851-4783-88b4-f0e27f2a6208__;!!IKRxdwAv5BmarQ!JvUD2xWRyAVskM-WLQWK5fElB8n-wsg9TgXIv2sJtcTR11nXI6Q34gBu5Jkulrn-3fUm$<https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Furldefense.com%2Fv3%2F__https%3A%2F%2Ffilesender.renater.fr%2F%3Fs%3Ddownload%26token%3Dbb336d91-7851-4783-88b4-f0e27f2a6208__%3B!!IKRxdwAv5BmarQ!JvUD2xWRyAVskM-WLQWK5fElB8n-wsg9TgXIv2sJtcTR11nXI6Q34gBu5Jkulrn-3fUm%24&data=04%7C01%7Cwinton-cornell%40utulsa.edu%7C8e8ac916d8244424905b08d8de5c2138%7Cd4ff013c62b74167924f5bd93e8202d3%7C0%7C1%7C637503834584411062%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=KGEinTMDuDge%2FfZUPyk815Eoat71tKnKuBl3PwZdhto%3D&reserved=0> >> <https://urldefense.com/v3/__https://filesender.renater.fr/?s=download&token=bb336d91-7851-4783-88b4-f0e27f2a6208__;!!IKRxdwAv5BmarQ!JvUD2xWRyAVskM-WLQWK5fElB8n-wsg9TgXIv2sJtcTR11nXI6Q34gBu5Jkulrn-3fUm$<https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Furldefense.com%2Fv3%2F__https%3A%2F%2Ffilesender.renater.fr%2F%3Fs%3Ddownload%26token%3Dbb336d91-7851-4783-88b4-f0e27f2a6208__%3B!!IKRxdwAv5BmarQ!JvUD2xWRyAVskM-WLQWK5fElB8n-wsg9TgXIv2sJtcTR11nXI6Q34gBu5Jkulrn-3fUm%24&data=04%7C01%7Cwinton-cornell%40utulsa.edu%7C8e8ac916d8244424905b08d8de5c2138%7Cd4ff013c62b74167924f5bd93e8202d3%7C0%7C1%7C637503834584411062%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=KGEinTMDuDge%2FfZUPyk815Eoat71tKnKuBl3PwZdhto%3D&reserved=0>> >> >> >> I did not put them on youtube or any public website since I do not own >> their rights but feel free to use them. Just acknowledge T. Yagi at >> ISSP, Univ. of Tokyo. >> >> He told me that the ice VI crystal sinking had been a challenge. It >> was hard to keep the focus on the DAC while rotating it and capturing >> a video at the time. >> >> Best, >> >> -- >> Sébastien Merkel >> >> UMET - Unité Matériaux et Transformations Université de Lille - CNRS >> https://urldefense.com/v3/__http://merkel.texture.rocks/__;!!IKRxdwAv5BmarQ!JvUD2xWRyAVskM-WLQWK5fElB8n-wsg9TgXIv2sJtcTR11nXI6Q34gBu5JkuluaiGydS$<https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Furldefense.com%2Fv3%2F__http%3A%2F%2Fmerkel.texture.rocks%2F__%3B!!IKRxdwAv5BmarQ!JvUD2xWRyAVskM-WLQWK5fElB8n-wsg9TgXIv2sJtcTR11nXI6Q34gBu5JkuluaiGydS%24&data=04%7C01%7Cwinton-cornell%40utulsa.edu%7C8e8ac916d8244424905b08d8de5c2138%7Cd4ff013c62b74167924f5bd93e8202d3%7C0%7C1%7C637503834584421060%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=yfDRo4jazfPMwufovIQpNnTj%2BskFstohVA2cCN2xaQM%3D&reserved=0> >> <https://urldefense.com/v3/__http://merkel.texture.rocks/__;!!IKRxdwAv5BmarQ!JvUD2xWRyAVskM-WLQWK5fElB8n-wsg9TgXIv2sJtcTR11nXI6Q34gBu5JkuluaiGydS$<https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Furldefense.com%2Fv3%2F__http%3A%2F%2Fmerkel.texture.rocks%2F__%3B!!IKRxdwAv5BmarQ!JvUD2xWRyAVskM-WLQWK5fElB8n-wsg9TgXIv2sJtcTR11nXI6Q34gBu5JkuluaiGydS%24&data=04%7C01%7Cwinton-cornell%40utulsa.edu%7C8e8ac916d8244424905b08d8de5c2138%7Cd4ff013c62b74167924f5bd93e8202d3%7C0%7C1%7C637503834584421060%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=yfDRo4jazfPMwufovIQpNnTj%2BskFstohVA2cCN2xaQM%3D&reserved=0>> >> >> Tel: +33 (0)3 20 43 65 16 >> E-mail: sebastien.merkel@univ-lille.fr<mailto:sebastien.merkel@univ-lille.fr> >> <mailto:sebastien.merkel@univ-lille.fr<mailto:sebastien.merkel@univ-lille.fr>> >> >> Le 24/02/2021 à 18:20, Kurt Leinenweber a écrit : >>> Hi, Japan Broadcasting Corporation (NHK) made a beautiful video >>> showing an ice V crystal sinking in the diamond cell (instead of >>> floating), in Takehiko Yagi's lab at ISSP back in 1989-1990 (I was a >>> postdoc). I think I still have a videotape copy but it is probably >>> available on the web. I have seen it used by others in seminar >>> lectures (without acknowledgment) including one or more of the groups >>> mentioned here! So that is probably what you saw... >>> >>> - Kurt >>> >>> >>> >>> >>> >>> -----Original Message----- >>> From: Robert Bodnar via MSA-talk <msa-talk@minlists.org<mailto:msa-talk@minlists.org>> >>> Sent: Wednesday, February 24, 2021 9:05 AM >>> To: Fred Marton <fmarton@bergen.edu<mailto:fmarton@bergen.edu>> >>> Cc: Sébastien Merkel <sebastien.merkel@univ-lille.fr<mailto:sebastien.merkel@univ-lille.fr>>; >>> msa-talk@minlists.org<mailto:msa-talk@minlists.org> >>> Subject: [MSA-talk] Re: [EXT] Re: Classroom demonstration of >>> decompression melting? >>> >>> I do recall seeing videos of this several years ago - maybe from >>> I-Ming Chou’s group or from Russ Hemley’s group? >>> >>> >>>> On Feb 24, 2021, at 10:47 AM, Fred Marton via MSA-talk >>>> <msa-talk@minlists.org<mailto:msa-talk@minlists.org>> wrote: >>>> >>>> A video of this would be great! >>>> >>>> On Wed, Feb 24, 2021 at 10:26 AM Sébastien Merkel via MSA-talk >>>> <msa-talk@minlists.org<mailto:msa-talk@minlists.org>> wrote: >>>> >>>> Not everyone has one, but pure water in the diamond anvil cell works >>>> well. You can look into your diamond cell with a microscope and >>>> camera and project the image. >>>> >>>> As you increase pressure to ~1 GPa, you form ice VI at ambient >>>> temperature, which you can melt by releasing pressure. >>>> >>>> >>>> -- >>>> Sébastien Merkel >>>> >>>> UMET - Unité Matériaux et Transformations Université de Lille - CNRS >>>> https://urldefense.com/v3/__http://merkel.texture.rocks/__;!!IKRxdwAv5BmarQ!JVpjgucslHOt_B3PEzJT91Scls30g21amM8XNqKjbmxCNEM9kfblTUqcvnDow2DxQXmd$<https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Furldefense.com%2Fv3%2F__http%3A%2F%2Fmerkel.texture.rocks%2F__%3B!!IKRxdwAv5BmarQ!JVpjgucslHOt_B3PEzJT91Scls30g21amM8XNqKjbmxCNEM9kfblTUqcvnDow2DxQXmd%24&data=04%7C01%7Cwinton-cornell%40utulsa.edu%7C8e8ac916d8244424905b08d8de5c2138%7Cd4ff013c62b74167924f5bd93e8202d3%7C0%7C1%7C637503834584431052%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=S4lK%2BpSj1eQa5MdZRKh9eNMGNExooEA2ai%2BOuGyzZ1k%3D&reserved=0> >>>> Tel: +33 (0)3 20 43 65 16 >>>> E-mail: sebastien.merkel@univ-lille.fr<mailto:sebastien.merkel@univ-lille.fr> >>>> >>>> Le 23/02/2021 à 21:51, Mark Rivers via MSA-talk a écrit : >>>>> Hi Mike, >>>>> >>>>> I have never tried it, but gallium seems like a good candidate but >>>>> for the opposite effect. The liquid is more dense than the solid, >>>>> so it melts as you apply pressure. It melts at 29.8 C (85.6 F) so >>>>> with just a little heating you can get it near its melting point in >>>>> the lab. Application of a little pressure should melt it. It >>>>> might be hard to observe in a vise, since as soon as pressure is >>>>> released (i.e. a droplet) it will freeze. >>>>> >>>>> Mark >>>>> >>>>> >>>>> -----Original Message----- >>>>> From: Mike Palin via MSA-talk <msa-talk@minlists.org<mailto:msa-talk@minlists.org>> >>>>> Sent: Tuesday, February 23, 2021 2:14 PM >>>>> To: msa-talk@minlists.org<mailto:msa-talk@minlists.org> >>>>> Subject: [MSA-talk] Classroom demonstration of decompression melting? >>>>> >>>>> Hello all- >>>>> >>>>> Does anyone know of a demonstration of decompression melting that >>>>> could be done "live" in a classroom? Ideally a nontoxic material >>>>> that is solid under compression (perhaps held in a vise) at near >>>>> room temperatures and visibly melts a bit when the pressure is >>>>> released. I know, too much to ask for. >>>>> >>>>> Cheers, >>>>> Mike >>>>> >>>>> ___________________________________________________ >>>>> Dr J. Michael Palin >>>>> Department of Geology >>>>> University of Otago >>>>> PO Box 56, Dunedin 9054 (post) >>>>> 360 Leith Street, North Dunedin 9016 (courier) New Zealand >>>>> +64-3-479-9083 (office) >>>>> +64-3-479-7527 (fax) >>>>> +64-3-479-7519 (admin) >>>>> ORCID 0000-0002-4972-7302 >>>>> _______________________________ >>>>> Who will prefer the jingle of jade pendants If they once have heard >>>>> stone growing in a cliff? >>>>> - Lao Tzu >>>>> _______________________________________________ >>>>> MSA-talk mailing list -- msa-talk@minlists.org<mailto:msa-talk@minlists.org> To unsubscribe send >>>>> an email to msa-talk-leave@minlists.org<mailto:msa-talk-leave@minlists.org> >>>>> _______________________________________________ >>>>> MSA-talk mailing list -- msa-talk@minlists.org<mailto:msa-talk@minlists.org> To unsubscribe send >>>>> an email to msa-talk-leave@minlists.org<mailto:msa-talk-leave@minlists.org> >>>>> >>>> _______________________________________________ >>>> MSA-talk mailing list -- msa-talk@minlists.org<mailto:msa-talk@minlists.org> To unsubscribe send an >>>> email to msa-talk-leave@minlists.org<mailto:msa-talk-leave@minlists.org> >>>> >>>> >>>> -- >>>> Fred Marton, PhD >>>> Department of Physical Sciences >>>> Bergen Community College >>>> 400 Paramus Rd. >>>> Paramus, NJ 07652-1508 >>>> +1-201-493-7518 >>>> _______________________________________________ >>>> MSA-talk mailing list -- msa-talk@minlists.org<mailto:msa-talk@minlists.org> To unsubscribe send an >>>> email to msa-talk-leave@minlists.org<mailto:msa-talk-leave@minlists.org> >>> _______________________________________________ >>> MSA-talk mailing list -- msa-talk@minlists.org<mailto:msa-talk@minlists.org> To unsubscribe send an >>> email to msa-talk-leave@minlists.org<mailto:msa-talk-leave@minlists.org> >>> >> _______________________________________________ >> MSA-talk mailing list -- msa-talk@minlists.org<mailto:msa-talk@minlists.org> >> To unsubscribe send an email to msa-talk-leave@minlists.org<mailto:msa-talk-leave@minlists.org> > _______________________________________________ MSA-talk mailing list -- msa-talk@minlists.org<mailto:msa-talk@minlists.org> To unsubscribe send an email to msa-talk-leave@minlists.org<mailto:msa-talk-leave@minlists.org> -- Fred Marton, PhD Department of Physical Sciences Bergen Community College 400 Paramus Rd. Paramus, NJ 07652-1508 +1-201-493-7518 -- Fred Marton, PhD Department of Physical Sciences Bergen Community College 400 Paramus Rd. Paramus, NJ 07652-1508 +1-201-493-7518

Dear American Mineralogist Readers, Below are the Paper Highlights for this month’s issue of the American Mineralogist: International Journal of Earth and Planetary Materials. You may also view the American Mineralogist Paper Highlights list at here (http://www.minsocam.org/MSA/Ammin/AM_NotableArticles.html). The DOI links below will take you to the abstract on GeoScienceWorld. If you have “IP” access via your institution’s library, it should reveal the whole paper. Consult your institution’s IT department or friendly librarian. If you have MSA membership, then authenticate in from the American Mineralogist menu (here<http://www.msapubs.org/> directly). Once at the portal page, click the right-side American Mineralogist link, enter your user name (e-mail address), and your password (membership number). Then search via your browser’s search tools for the paper you want to read. (On Rachel’s computer, it is control-f but we think that is little different for everyone.) Note that on GSW you can sign up for a table of contents to be sent you when the issue is live -- this is a feature open to anyone who registers on the site. Thank you for reading American Mineralogist. Sincerely, Hongwu Xu Don Baker An evolutionary system of mineralogy, Part III: Primary chondrule mineralogy (4566 to 4561 Ma) https://doi.org/10.2138/am-2020-7564 The evolutionary system of mineralogy relies on varied physical and chemical attributes, including trace elements, isotopes, solid and fluid inclusions, and other information-rich characteristics. To understand processes of mineral formation and to place natural condensed phases in the deep-time context of planetary evolution, Hazen et al. add Part III of their evolutionary system that considers the formation of 43 different primary mineral phases in chondrules, which are igneous droplets that formed early in the history of the solar system, more than 4.56 billion years ago. Raman Spectroscopy Study of Manganese Oxides - Layer Structures https://doi.org/10.2138/am-2021-7666 Micro-Raman is a powerful tool for identification and characterization of biotic and abiotic Mn oxide phases from diverse natural settings (including on other planets) and thereby can provide new insights into the roles of these phases in our environment. Post et al. provide results from what they believe is the most comprehensive analysis of the Raman spectra for layer-structure Mn oxide phases to date, collected from a large number and variety of natural and synthetic samples, drawing from the Smithsonian Institution's extensive collection of Mn oxide specimens, and elsewhere. In many cases, the specimens have been characterized in detail using supplementary techniques. Additionally, Post et al. present representative spectra from different specimens, localities, and crystal orientations. A major goal of this study is to provide a comprehensive base of information (a spectral database is provided as supplementary data) that can be used for identifying the various Mn oxide mineral phases, with an emphasis on natural samples. Finally, Post et al. explore spectral trends for some specific phases that provide insights about composition, crystal structure, symmetry, and in some circumstances, Mn oxidation states. Raman signatures of the distortion and stability of MgCO3 to 75 GPa https://doi.org/10.2138/am-2020-7490 Zhao et al. report the Raman modes of natural magnesite, MgCO3 , up to 75 GPa at room temperature. They detected abnormal behavior in MgCO3, including the splitting of Raman peaks of T and v4 modes at approximately 30 and 50 GPa, respectively. The phenomena are assigned as MgCO3-Ib and MgCO3-Ic produced by the rotation of MgO6 octahedra. The distorted environment of the chemical bond would greatly improve the stability of magnesite over a large pressure and temperature range in relation to its melting or decomposition. Both experimental and theoretical evidence indicates that the diversity of distorted structural environments, including corner-sharing CO4 tetrahedra forming C3O9 three-membered rings. Compared to the low-pressure threefold coordinated carbonates (CO3)2-triangles in the structure, the tetrahedrally coordinated carbonates are expected to exhibit substantially different reactivity and different chemical properties in the liquid state. These crystallographic characteristics in carbonates may play an important role in deep carbon reservoirs and fluxes in the deep Earth. Furthermore, the bonding strength in MgCO3 changes through lattice distortion and structural transition, likely impacting the distribution of carbon and magnesium isotopes in the deep mantle. Competitive adsorption geometries for the arsenate As(V) and phosphate P(V) oxyanions on magnetite surfaces: Experiments and theory https://doi.org/10.2138/am-2020-7350 Adsorption of arsenate and phosphate on magnetite was studied by Liang et al. using in situ ATR and 2D-COS. Monodentate mononuclear and bidentate binuclear complexes dominate in phosphate adsorption. Arsenate forms bidentate binuclear complexes with fewer outer-sphere species. Arsenate displays a higher competitive ability than phosphate. The competitive ability is related to adsorption geometry and the heterogeneity of surface active sites. Probing transformation path from aluminum (oxy)hydroxides (boehmite, bayerite, and gibbsite) to metastable alumina: A view from high-resolution 27Al MAS NMR https://doi.org/10.2138/am-2020-7481 Kim and Lee investigated the dehydration paths to metastable alumina from various aluminum (oxy)hydroxide precursors (i.e., boehmite, bayerite, and gibbsite) in the low-temperature range (~300 °C) using high-resolution 27Al NMR. The results confirm that the phase transformation paths depend on the type of precursor minerals. The precursor-dependent structural evolution in the low-temperature range helps to understand the geological processes involving metastable phases and their dehydration in the Earth's surface environments. Crystal structure of K-cymrite and kokchetavite from single-crystal X-ray diffraction https://doi.org/10.2138/am-2020-7407 Romanenko et al. report their investigation of K-cymrite (KAlSi3O8+H2O) and kokchetavite (KAlSi3O8, IMA-2004-011), which were earlier identified as mineral inclusions in ultra-high pressure metamorphic crustal rocks. However, their crystal structures previously were only guessed on the basis of powder X-ray diffraction patterns. Romanenko et al. present the crystal structures of K-cymrite and kokchetavite by single-crystal X-ray diffraction. For kokchetavite a new space group and unit cell were identified. In addition, the spectroscopic and Thermogravitational data provide important information for the identification and interpretation of these phases in mineral inclusions. Fluid source and metal precipitation mechanism of sediment-hosted Chang'an orogenic gold deposit, SW China: constraints from sulfide texture, trace element, S, Pb and He-Ar isotopes, and calcite C-O isotopes https://doi.org/10.2138/am-2020-7508 Yang et al. highlight that ore metals in sediment-hosted disseminated orogenic gold deposits can be sourced from both deep fluids and local wallrock and that fluid-rock interaction behaved as a key control on ore precipitation. Iron isotope fractionation in reduced hydrothermal gold deposits: A case study from the Wulong gold deposit, Liaodong Peninsula, East China https://doi.org/10.2138/am-2020-7534 Pyrite and pyrrhotite are the major Fe-bearing minerals of the quartz-sulfide veins in the Wulong reduced gold deposit. Iron isotope fractionation modeling by Zheng et al. shows that under relatively low oxygen fugacity conditions, pyrrhotite with light δ56Fe crystallized first from the initial ore-forming fluids, resulting in ore-forming fluids with elevated δ56Fe values. Due to an increase of oxygen fugacity, pyrite with heavy δ56Fe started to precipitate later. The iron isotopic compositions provide a new perspective for the initial redox conditions and evolution of the Wulong gold deposit, which are important to trace the source of ore-forming materials and further exploration. Tungsten mineralization during the evolution of a magmatic-hydrothermal system: mineralogical evidence from the Xihuashan rare-metal granite in South China https://doi.org/10.2138/am-2020-7514 Micas can record the magmatic-hydrothermal evolution of tungsten granite. Li et al. demonstrate that the geochemical variations and textures of zoned micas indicate magmatic fluids, rather than external fluids, were involved in greisenization. The siderite present is related to a Fe, Mn, and CO2-rich fluid under reducing conditions. The greisenization process plays a critical role in tungsten mineralization. The reducing environment and the mixture of a W-rich solution and a Fe-, Mn-rich external fluid facilitated tungsten mineralization. Crystallization and melt extraction of a garnet-bearing charnockite from South China: Constraints from petrography, geochemistry, mineral thermometer and rhyolite-MELTS modeling https://doi.org/10.2138/am-2020-7335Zhang et al. investigated the Yunlu garnet-bearing charnockite as an example of the very few peraluminous magmatic charnockites around the world. The magmatic pressure-temperature-melt H2O content and associated crystallization of the charnockite was constrained quantitatively by the integration of petrography, geochemistry, fluid inclusion investigations, mineral thermo-barometry, and thermodynamic modeling. The Yunlu magma solidified at "wet" (H2O-saturated) and "cold" (~630 °C) conditions, which is different from metaluminous charnockites that solidified at "dry" (H2O-unsaturated) and "hot" (>800 °C) conditions. This study indicates that the peraluminous charnockites may experience a distinct crystallization process compared to metaluminous charnockites. Meanwhile, the temperature discrepancies between mineral thermometer results and the magmatic solidus were interpreted by the "melt extraction" model. The study sheds new light on the interpretations of granite thermometry. Reducing epistemic and model uncertainty in ionic inter-diffusion chronology: A 3D observation and dynamic modeling approach using olivine from Piton de la Fournaise, La Réunion https://doi.org/10.2138/am-2021-7296CCBYModeling of Mg-Fe zonation in olivine crystals from mafic ejecta and deposits from volcanic eruptions is an often-used tool for calculating magmatic timescales, but sub-perfect diffusion profiles are often rejected. This is a bias that Couperthwaite et al. suggest should, and can, be addressed as a community. The results in this open access paper by Couperthwaite et al. unlock the majority of these profiles and, in doing so, reveal a richer view of magmatic processes than previously could be seen. Erratum Memorial of James J. Papike