Home PageAbout MindatThe Mindat ManualHistory of MindatCopyright StatusWho We AreContact UsAdvertise on Mindat
Donate to MindatCorporate SponsorshipSponsor a PageSponsored PagesMindat AdvertisersAdvertise on Mindat
Learning CenterWhat is a mineral?The most common minerals on earthInformation for EducatorsMindat ArticlesThe ElementsThe Rock H. Currier Digital LibraryGeologic Time
Minerals by PropertiesMinerals by ChemistryAdvanced Locality SearchRandom MineralRandom LocalitySearch by minIDLocalities Near MeSearch ArticlesSearch GlossaryMore Search Options
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
Mining CompaniesStatisticsUsersMineral MuseumsClubs & OrganizationsMineral Shows & EventsThe Mindat DirectoryDevice SettingsThe Mineral Quiz
Photo SearchPhoto GalleriesSearch by ColorNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day GalleryPhotography
╳Discussions
💬 Home🔎 Search📅 LatestGroups
EducationOpen discussion area.Fakes & FraudsOpen discussion area.Field CollectingOpen discussion area.FossilsOpen discussion area.Gems and GemologyOpen discussion area.GeneralOpen discussion area.How to ContributeOpen discussion area.Identity HelpOpen discussion area.Improving Mindat.orgOpen discussion area.LocalitiesOpen discussion area.Lost and Stolen SpecimensOpen discussion area.MarketplaceOpen discussion area.MeteoritesOpen discussion area.Mindat ProductsOpen discussion area.Mineral ExchangesOpen discussion area.Mineral PhotographyOpen discussion area.Mineral ShowsOpen discussion area.Mineralogical ClassificationOpen discussion area.Mineralogy CourseOpen discussion area.MineralsOpen discussion area.Minerals and MuseumsOpen discussion area.PhotosOpen discussion area.Techniques for CollectorsOpen discussion area.The Rock H. Currier Digital LibraryOpen discussion area.UV MineralsOpen discussion area.Recent Images in Discussions
Mineralogical ClassificationCrystal structure of bassetite and saléeite
5th Mar 2016 18:21 UTCUwe Kolitsch Manager
The crystal structures of two autunite-group minerals have been solved recently. The crystal structure of bassetite, Fe2+[(UO2)(PO4)]2(H2O)10, from the type locality in Cornwall, United Kingdom (Basset Mines) was solved for the first time. Bassetite is monoclinic, space group P21/n, a = 6.961(1), b = 20.039(2), c = 6.974(1) Å and β = 90.46(1)°. The crystal structure of saléeite, Mg[(UO2)(PO4)]2(H2O)10, from Shinkolobwe, Democratic Republic of Congo, was also solved. Saléeite is monoclinic, space group P21/n, a = 6.951(1), b = 19.942(1), c = 6.967(1)Å and β = 90.58(1)°. The crystal structure investigation of bassetite (R1 = 0.0658 for 1879 observed reflections with |Fo| ≥ 4σF) and saléeite (R1 = 0.0307 for 1990 observed reflections with |Fo| ≥ 4σF) confirms that both minerals are topologically identical and that bassetite contains ten water molecules per formula unit. Their structure contains autunite-type sheets, [(UO2)(PO4)]-, consisting of corner-sharing UO6 square bipyramids and PO4 tetrahedra. Iron and magnesium are surrounded by water molecules to form Fe(H2O)6 or Mg(H2O)6 octahedra located in interlayer, between the autunite-type sheets. Two isolated independent water molecules are also located in interlayer. Energy-dispersive X-ray spectroscopy analysis confirmed the chemical composition obtained from structure refinement. These new data prompt a re-assessment of minerals of the autunite and meta-autunite groups.
Note that the bassetite formula was previously assumed to have only 8H2O.
Mineral pages updated.
Mindat.org is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2024, except where stated. Most political location boundaries are © OpenStreetMap contributors. Mindat.org relies on the contributions of thousands of members and supporters. Founded in 2000 by Jolyon Ralph.
Privacy Policy - Terms & Conditions - Contact Us / DMCA issues - Report a bug/vulnerability Current server date and time: April 26, 2024 10:20:10
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2024, except where stated. Most political location boundaries are © OpenStreetMap contributors. Mindat.org relies on the contributions of thousands of members and supporters. Founded in 2000 by Jolyon Ralph.
Privacy Policy - Terms & Conditions - Contact Us / DMCA issues - Report a bug/vulnerability Current server date and time: April 26, 2024 10:20:10