Vote for your favorite mineral in #MinCup26! - Monazite-(Ce) vs. Andalusite
It's a showdown with rare earth elemental ore Monazite-(Ce) and index mineral Andalusite.
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

Biotite from
Penn ar Roc'h - Porz an Ejen area, Ushant, Brest, Finistère, Brittany, France


Locality type:Area
Classification
Species:'Biotite' (not an IMA approved species)
Formula:K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
Confirmation
Validity:Believed Valid
Data
Mineral Data:Click here to view Biotite data
Locality Data:Click here to view Penn ar Roc'h - Porz an Ejen area, Ushant, Brest, Finistère, Brittany, France
Data Identifiers
Mindat Occurrence Record ID:962656
Long-form Identifier:1:3:962656:0
GUID (UUID V4):0
Nearest other occurrences of Biotite
21.9km (13.6 miles) ⓘRuscumunoc beach alluvial deposits, Ruscumunoc, Plouarzel, Brest, Finistère, Brittany, France
24.3km (15.1 miles) ⓘRocher du Crapaud beach alluvials, Lanildut, Brest, Finistère, Brittany, France
25.0km (15.6 miles) ⓘBlancs Sablons beach alluvials, Le Conquet, Brest, Finistère, Brittany, France
32.5km (20.2 miles) ⓘTrégana beach alluvials, Trégana, Locmaria-Plouzané, Brest, Finistère, Brittany, France
40.4km (25.1 miles) ⓘGuélet ar C'hoat, Plouguin, Brest, Finistère, Brittany, France
42.5km (26.4 miles) ⓘWrac'h island, Lilia, Plouguerneau, Brest, Finistère, Brittany, France
47.1km (29.3 miles) ⓘPlas ar Skoul, Sein Island, Quimper, Finistère, Brittany, France
47.8km (29.7 miles) ⓘNerroth island, Sein Island, Quimper, Finistère, Brittany, France
50.2km (31.2 miles) ⓘPointe du Van, Cléden-Cap-Sizun, Quimper, Finistère, Brittany, France
51.4km (32.0 miles) ⓘPointe du Raz, Plogoff, Quimper, Finistère, Brittany, France
References
Chauris, L. (2014) Minéraux de Bretagne [Minerals of Brittany]. Les Editions du Piat. 336pp.p.42
 
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 7, 2026 13:16:41
Go to top of page