# Krotite

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> Markdown URL: https://mediated.wiki/source/Krotite.md
> Source: https://en.wikipedia.org/wiki/Krotite
> Source revision: 1310123164
> License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/)

{{Short description|Natural mineral}}
{{Infobox mineral
| name =   Krotite
| category    = [Oxide mineral](/source/Oxide_mineral)
| boxwidth    = 
| boxbgcolor  = 
| image       = 
| imagesize   = 
| alt         = 
| caption     = 
| formula     = CaAl<sub>2</sub>O<sub>4</sub>
| IMAsymbol   = Kro<ref>{{Cite journal|last=Warr|first=L.N.|date=2021|title=IMA–CNMNC approved mineral symbols|journal=Mineralogical Magazine|volume=85|issue=3|pages=291–320|doi=10.1180/mgm.2021.43|bibcode=2021MinM...85..291W|s2cid=235729616|doi-access=free}}</ref>
| molweight   = 
| strunz      = 
| dana        = 
| system      = [Monoclinic](/source/Monoclinic)
| class       = Prismatic (2/m) <br/><small>(same [H-M symbol](/source/H-M_symbol))</small>
| symmetry    = ''P2''<sub>1</sub>/n
| unit cell   = a = 8.6996(3)&nbsp;[Å](/source/%C3%85ngstrom) <br/>b = 8.0994(3)&nbsp;Å <br/>c = 15.2170(11)&nbsp;Å <br/>β = 90.188(6)°; Z&nbsp;=&nbsp;12
| color       = Colorless
| colour      = 
| habit       = 
| luster      = Vitreous
| streak      = White
| diaphaneity  = Transparent
| mohs        = 6.5
| gravity     = 2.94
| references  = <ref name=Mindat>{{citation|url=http://www.mindat.org/min-40468.html|title= Krotite|publisher= Mindat.org}}</ref><ref name=AmMin/>
}}

'''Krotite''' is a natural [mineral](/source/mineral) composed of [calcium](/source/calcium), [aluminium](/source/aluminium) and [oxygen](/source/oxygen), with the molecular formula CaAl<sub>2</sub>O<sub>4</sub>. It is the low-pressure [dimorph](/source/dimorph) of CaAl<sub>2</sub>O<sub>4</sub>, of which the high-pressure dimorph is named [dmitryivanovite](/source/dmitryivanovite).

Krotite was reported in 2011<ref name=AmMin>{{cite journal |last1=Ma |first1=Chi|last2=Kampf|first2=Anthony R. |last3=Connolly Jr. |first3=Harold C. |last4=Beckett |first4=John R. |last5=Rossman |first5=George R. |last6=Sweeney Smith |first6=Stuart A. |last7=Schrader |first7=Devin L. |title = Krotite, CaAl<sub>2</sub>O<sub>4</sub>, a new refractory mineral from the NWA 1934 meteorite|journal=American Mineralogist |volume=96 |pages=709–715 |date=2011|url = http://www.minsocam.org/MSA/AmMin/TOC/2011/MJ11.html |doi=10.2138/am.2011.3693 |issue=5–6|bibcode=2011AmMin..96..709M |s2cid=8236133|url-access=subscription }}</ref> in a [calcium-aluminium-rich inclusion](/source/calcium-aluminium-rich_inclusion) (CAI) in the [carbonaceous chondrite](/source/carbonaceous_chondrite) [meteorite](/source/meteorite) NWA (North West Africa) 1934, which landed in [Morocco](/source/Morocco).<ref>{{Cite web|url=http://www.kitv.com/news/27977944/detail.html|title=Honolulu, Hawaii news, sports & weather - KITV Channel 4}}</ref> The mineral name was approved by the [International Mineralogical Association](/source/International_Mineralogical_Association) (IMA 2010-038)<ref>{{cite journal|url=http://pubsites.uws.edu.au/ima-cnmnc/CNMNC%20NEWSLETTER%205.pdf|title=New minerals approved by the IMA-CNMNC in September 2010|journal=Mineralogical Magazine|date=2010|volume=74|issue=5|pages=899–902|author=P. A. Williams|doi=10.1180/S0026461X00056036|s2cid=232394841|display-authors=etal|archive-date=2012-03-20|access-date=2011-05-07|archive-url=https://web.archive.org/web/20120320181827/http://pubsites.uws.edu.au/ima-cnmnc/CNMNC%20NEWSLETTER%205.pdf|url-status=dead}}</ref> and honors Alexander N. Krot, a researcher in [cosmochemistry](/source/cosmochemistry) at the [University of Hawaii at Manoa](/source/University_of_Hawaii_at_Manoa) in Honolulu, Hawaii.<ref name=Cosmosparks/>

Researchers have found that the mineral, which has the same atomic arrangement as a man-made component of some types of [concrete](/source/concrete) (specifically, [calcium aluminate cements](/source/calcium_aluminate_cements)), forms under low [pressure](/source/pressure) at a [temperature](/source/temperature) of at least {{convert|1500|C|F|abbr=on}}. These conditions of high temperature and low pressure are consistent with a hypothesis that the krotite grains found in the meteorite formed as high-temperature [condensate](/source/Condensation_reaction)s from the [solar nebula](/source/solar_nebula) from which the [Solar System](/source/Solar_System) formed, approximately 4.6 billion years ago. Thus, they are likely to be among the earliest minerals formed in the Solar System.<ref>{{citation|title = Paper announces discovery of 1 of earliest minerals formed in solar system|publisher = Eurekalert|date = May 6, 2011|url = http://www.eurekalert.org/pub_releases/2011-05/nhmo-pad050611.php|access-date = May 6, 2011|archive-date = June 9, 2021|archive-url = https://web.archive.org/web/20210609032304/https://www.eurekalert.org/pub_releases/2011-05/nhmo-pad050611.php|url-status = dead}}</ref>

The CAI containing the krotite was said to resemble a "cracked egg" because its rim was crosscut by cracks filled with [iron](/source/iron_hydroxide) and [aluminum hydroxide](/source/aluminum_hydroxide)s. Researchers suggest that the mineral assemblage in the CAI was at one time surrounded by a hot [gas](/source/gas) that reacted with krotite crystals on the surface of the CAI. It is likely that cracks on this rim of the CAI were filled with hydrated oxides as a result of [weathering](/source/weathering) that occurred after the meteorite landed on Earth.<ref name=Cosmosparks>{{citation|last=Martel |first=Linda|title = Discovery of New Mineral, Krotite, in a CAI|publisher = Planetary Science Research Discoveries, CosmoSparks Report|date = May 6, 2011|url = http://www.psrd.hawaii.edu/CosmoSparks/May11/krotite.html}}</ref>

Associated minerals include [perovskite](/source/perovskite), [gehlenite](/source/gehlenite), [hercynite](/source/hercynite), [mayenite](/source/mayenite), [grossite](/source/grossite), [hibonite](/source/hibonite), [spinel](/source/spinel) and [diopside](/source/diopside).<ref name=AmMin/>

==See also==
* [Glossary of meteoritics](/source/Glossary_of_meteoritics)
 
==References==
{{reflist}}

{{Meteorites}}

Category:Calcium minerals
Category:Aluminium minerals
Category:Oxide minerals
Category:Meteorite minerals
Category:Monoclinic minerals
Category:Minerals in space group 14

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Adapted from the Wikipedia article [Krotite](https://en.wikipedia.org/wiki/Krotite) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Krotite?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.