{"id":16837,"date":"2018-12-01T08:00:30","date_gmt":"2018-12-01T07:00:30","guid":{"rendered":"http:\/\/karmaka.de\/?p=16837"},"modified":"2018-12-01T08:00:30","modified_gmt":"2018-12-01T07:00:30","slug":"maohokite-a-post%e2%80%90spinel-polymorph-of-mgfe2o4-in-shocked-gneiss-from-the-xiuyan-crater-in-china","status":"publish","type":"post","link":"https:\/\/karmaka.de\/?p=16837","title":{"rendered":"Maohokite, a post\u2010spinel polymorph of MgFe2O4 in shocked gneiss from the Xiuyan crater in China<span class=\"badge-status\" style=\"background:#787878\">OPEN ACCESS<\/span>&nbsp;"},"content":{"rendered":"<p>Ming Chen, Jinfu Shu, Xiande Xie, Dayong Tan<\/p>\n<p>Meteoritics &#038; Planetary Science<br \/>\nFirst Published: 30 November 2018<\/p>\n<p><a href=\"https:\/\/onlinelibrary.wiley.com\/doi\/full\/10.1111\/maps.13222\" target=\"_blank\"><strong>LINK<\/strong><\/a><\/p>\n<p>&#8220;Maohokite, a post\u2010spinel polymorph of MgFe2O4, was found in shocked gneiss from the Xiuyan crater in China. Maohokite in shocked gneiss coexists with diamond, reidite, TiO2\u2010II, as well as diaplectic glasses of quartz and feldspar. Maohokite occurs as nano\u2010sized crystallites. The empirical formula is (Mg0.62Fe0.35Mn0.03)2+Fe3+2O4. In situ synchrotron X\u2010ray microdiffraction established maohokite to be orthorhombic with the CaFe2O4\u2010type structure. The cell parameters are a = 8.907 (1) \u00c5, b = 9.937(8) \u00c5, c = 2.981(1) \u00c5; V = 263.8 (3) \u00c53; space group Pnma. The calculated density of maohokite is 5.33 g cm\u22123. Maohokite was formed from subsolidus decomposition of ankerite Ca(Fe2+,Mg)(CO3)2 via a self\u2010oxidation\u2010reduction reaction at impact pressure and temperature of 25\u201345 GPa and 800\u2013900 \u00b0C. The formation of maohokite provides a unique example for decomposition of Fe\u2010Mg carbonate under shock\u2010induced high pressure and high temperature. The mineral and its name have been approved by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (IMA 2017\u2010047). The mineral was named maohokite after Hokwang Mao, a staff scientist at the Geophysical Laboratory, Carnegie Institution of Washington, for his great contribution to high pressure research. &#8220;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Ming Chen, Jinfu Shu, Xiande Xie, Dayong Tan Meteoritics &#038; Planetary Science First Published: 30 November 2018 LINK &#8220;Maohokite, a post\u2010spinel polymorph of MgFe2O4, was found in shocked gneiss from the Xiuyan crater in China&#8230;.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[90],"tags":[4760,4761],"_links":{"self":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/16837"}],"collection":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=16837"}],"version-history":[{"count":1,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/16837\/revisions"}],"predecessor-version":[{"id":16838,"href":"https:\/\/karmaka.de\/index.php?rest_route=\/wp\/v2\/posts\/16837\/revisions\/16838"}],"wp:attachment":[{"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=16837"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=16837"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/karmaka.de\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=16837"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}