Vote for your favorite mineral in #MinCup26! - Erythrite vs. Skutterudite
Pretty pink and poisonous Erythrite is against its shiny silver and structurally-useful Skutterudite.
Log InRegister
Quick Links : The Mindat ManualThe Rock H. Currier Digital LibraryMindat Newsletter [Free Download]
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 TimeExplore Fossils
Minerals by PropertiesMinerals by ChemistryMineral Visual ExplorerAdvanced Locality SearchRandom MineralRandom LocalitySearch by minIDLocalities Near MeSearch ArticlesSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
Keyword(s):
 
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
Mining CompaniesStatisticsUsersMineral MuseumsClubs & OrganizationsMineral Shows & EventsThe Mindat DirectoryDevice SettingsThe Mineral QuizTime Machine
Photo SearchPhoto GalleriesSearch by ColorPhoto Colour ExplorerNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day GalleryPhotography

UM1994-05-F:OREE

A synonym of Håleniusite-(Ce)
This page is currently not sponsored. Click here to sponsor this page.
Formula:
(Ce,La)OF
Synonym:
A synonym of Håleniusite-(Ce)
Co-described with UM1994-05-F:OREE and 'Unnamed (Lanthanum Oxyfluoride)'. Apparently the second natural cerium oxyhalide.

Seems to be the Ce-dominant analogue of håleniusite-(La).

As intimately intergrown aggregates (of the two), up to 200 microns in diameter, in quartz and zinnwaldite interstices, in a drill core.

Electron microprobe wt.% data (one of 4 analyses): ThO2 4.20, La2O3 15.70, Ce2O3 58.25, Pr2O3 3.01, Nd2O3 8.38, Sm2O3 2.10, Dy2O3 0.11, Y2O3 0.26, CaO 2.03, F 11.24, 0~F 4.73, total 100.61. This corresponds to the empirical formula of (Ce0.605La0.164Nd0.085Ca0.062Pr0.031Th0.027Sm0.021Y0.004Dy0.001)O0.978F1.008.

Of the composite PXRD pattern 8 reflections were attributed to this phase. Seem to possess bastnäsite-type hexagonal cell: a=7.007(10), c=9.840(15); D(calc=6.25 g/cm3; Z=9.


Hide all sections | Show all sections

Unique IdentifiersHide

Mindat ID:
53508 (as UM1994-05-F:OREE)
55595 (as Håleniusite-(Ce))
Long-form identifier:
mindat:1:1:53508:9 (as UM1994-05-F:OREE)
mindat:1:1:55595:9 (as Håleniusite-(Ce))

Similar NamesHide

Internet Links for UM1994-05-F:OREEHide

References for UM1994-05-F:OREEHide

Quick NavTopUnique IdentifiersSimilar NamesInternet Links References
 
and/or  
Mindat.org® is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization. Mindat® and mindat.org® are registered trademarks of the Hudson Institute of Mineralogy.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2026, 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 and Ida Chau.
Content on this site may not be used to train, fine-tune, or otherwise develop artificial intelligence or machine learning models without prior written permission - see our Terms & Conditions.
To cite: Ralph, J., Von Bargen, D., Martynov, P., Zhang, J., Que, X., Prabhu, A., Morrison, S. M., Li, W., Chen, W., & Ma, X. (2025). Mindat.org: The open access mineralogy database to accelerate data-intensive geoscience research. American Mineralogist, 110(6), 833–844. doi:10.2138/am-2024-9486.
Privacy Policy - Terms & Conditions - Contact Us / DMCA issues - Report a bug/vulnerability Current server date and time: September 2, 2026 19:10:37 Page updated: January 10, 2026 06:47:54
Go to top of page