Vote for your favorite mineral in #MinCup26! - Cuprite vs. Orpiment
entice people to vote
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
Benjamin Franklin Mine, Chester Springs, West Pikeland Township, Chester County, Pennsylvania, 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 Benjamin Franklin Mine, Chester Springs, West Pikeland Township, Chester County, Pennsylvania, USA
Data Identifiers
Mindat Occurrence Record ID:360086
Long-form Identifier:1:3:360086:3
GUID (UUID V4):0
Nearest other occurrences of Biotite
13.0km (8.1 miles) ⓘFrench Creek Mines, Saint Peters, Warwick Township, Chester County, Pennsylvania, USA
21.6km (13.4 miles) ⓘCoatesville pegmatite locality, Coatesville, Chester County, Pennsylvania, USA
21.9km (13.6 miles) ⓘOld Perkiomen Mine, Lower Frederick Township, Montgomery County, Pennsylvania, USA
24.0km (14.9 miles) ⓘGrace Mine, Morgantown, Berks County, Pennsylvania, USA
28.3km (17.6 miles) ⓘDeshong's Quarry, Leiperville, Ridley Township, Delaware County, Pennsylvania, USA
30.1km (18.7 miles) ⓘMiquon (Miquon Station; Lafayette; Lafayette Station), Whitemarsh Township, Montgomery County, Pennsylvania, USA
34.3km (21.3 miles) ⓘWissahickon Valley, Philadelphia, Philadelphia County, Pennsylvania, USA
35.7km (22.2 miles) ⓘHoopes Dam, New Castle County, Delaware, USA
36.0km (22.3 miles) ⓘComley's Quarry, Germantown, Philadelphia, Philadelphia County, Pennsylvania, USA
36.0km (22.3 miles) ⓘWooddale Quarries, Wooddale, New Castle County, Delaware, USA
References
Geyer, Smith, Barnes, pgs. 85-86
Min. Col. in PA (1976)
 
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 5, 2026 00:04:51
Go to top of page