Vote for your favorite mineral in #MinCup26! - Bournonite vs. Vesuvianite
Cogwheels of bournonite are up against colourful vesuvianite.
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
Pohndorf Mine, Toll Mountain, Boulder Batholith, Jefferson County, Montana, USA


Locality type:Mine
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 Pohndorf Mine, Toll Mountain, Boulder Batholith, Jefferson County, Montana, USA
Data Identifiers
Mindat Occurrence Record ID:495476
Long-form Identifier:1:3:495476:7
GUID (UUID V4):0
Nearest other occurrences of Biotite
17.9km (11.1 miles) ⓘAltona Mine, Butte Mining District (Summit Valley Mining District), Silver Bow County, Montana, USA
18.6km (11.6 miles) ⓘMontgomery Mine, Butte Mining District (Summit Valley Mining District), Silver Bow County, Montana, USA
18.7km (11.6 miles) ⓘContinental Pit, Butte Mining District (Summit Valley Mining District), Silver Bow County, Montana, USA
19.0km (11.8 miles) ⓘSarsfield Mine, Butte Mining District (Summit Valley Mining District), Silver Bow County, Montana, USA
19.1km (11.9 miles) ⓘNorthwestern Mine, Butte Mining District (Summit Valley Mining District), Silver Bow County, Montana, USA
21.7km (13.5 miles) ⓘGem Mine, Butte Mining District (Summit Valley Mining District), Silver Bow County, Montana, USA
21.8km (13.5 miles) ⓘSteward Mine, Butte Mining District (Summit Valley Mining District), Silver Bow County, Montana, USA
22.6km (14.1 miles) ⓘLexington Mine, Walkerville, Butte Mining District (Summit Valley Mining District), Silver Bow County, Montana, USA
26.3km (16.3 miles) ⓘGolden Sunlight Mine, Whitehall Mining District (Cardwell Mining District), Jefferson County, Montana, USA
35.6km (22.1 miles) ⓘGilliam prospect, Madison County, Montana, USA
References
(2005) Mineral Resources Data System (MRDS), US Geological Survey.
 
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 4, 2026 06:11:18
Go to top of page