Log InRegister
Search For:
Mineral Name:
Locality Name:
Keyword(s):
 
Home PageAbout MindatThe Mindat ManualHistory of MindatCopyright StatusWho We AreOur ScienceMindat Newsletter [Free Download]Contact Us
Donate to MindatSponsor a PageCorporate SponsorshipSponsored Pages
Learning CenterWhat Is a Mineral?The Most Common Minerals on EarthInformation for EducatorsMindat ArticlesMindat Newsletter [Free Download]The ElementsThe Mineral Quiz
Search FormMinerals by PropertiesMinerals by ChemistryMineral Visual ExplorerAdvanced Locality SearchRandom MineralRandom LocalitySearch by minIDMinerals by CountryAlphabetical Mineral IndexAlphabetical Locality SearchMineral Association SearchList of CountriesLocalities Near MePhoto SearchSearch ArticlesSearch GlossaryThe Rock H. Currier Digital LibraryMore Search Options
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
MineralsPetrologyFossilsMeteoritesGeologic Time
Mining CompaniesStatisticsMineral MuseumsClubs & OrganizationsMineral Shows & EventsDevice SettingsTime Machine
Read DiscussionsIdentification Request
Photo SearchPhoto GalleriesSearch by ColourPhoto Colour ExplorerNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day GalleryPhotography

Biotite from
Cotopaxi Feldspar Mine (Cotopaxi Feldspar prospect; Henry pegmatite), Cotopaxi Pegmatite area, Cotopaxi, Cotopaxi Mining District, Fremont County, Colorado, 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 Cotopaxi Feldspar Mine (Cotopaxi Feldspar prospect; Henry pegmatite), Cotopaxi Pegmatite area, Cotopaxi, Cotopaxi Mining District, Fremont County, Colorado, USA
Data Identifiers
Mindat Occurrence Record ID:34982
Long-form Identifier:1:3:34982:0
GUID (UUID V4):0
Nearest other occurrences of Biotite
1.1km (0.7 miles) ⓘColorado Feldspar Pegmatite, Cotopaxi Mining District, Fremont County, Colorado, USA
4.6km (2.9 miles) ⓘCotopaxi Mining District, Fremont County, Colorado, USA
4.9km (3.0 miles) ⓘCotopaxi Mine (Cotopaxi lode; Gumaer Mine; Fannie lode; Fannie Mill), Mine Gulch, Cotopaxi, Cotopaxi Mining District, Fremont County, Colorado, USA
7.5km (4.7 miles) ⓘPine Ridge pegmatite, Cotopaxi Pegmatite area, Cotopaxi, Cotopaxi Mining District, Fremont County, Colorado, USA
8.2km (5.1 miles) ⓘMcCoy prospects, Cotopaxi Pegmatite area, Cotopaxi, Cotopaxi Mining District, Fremont County, Colorado, USA
9.5km (5.9 miles) ⓘDevil's Hole Mine, Fremont County, Colorado, USA
9.6km (5.9 miles) ⓘKnob Hill prospect (Knob Hill pegmatite), Howard, Cotopaxi Mining District, Fremont County, Colorado, USA
9.8km (6.1 miles) ⓘSchaaf prospect, Cotopaxi Pegmatite area, Cotopaxi, Cotopaxi Mining District, Fremont County, Colorado, USA
10.1km (6.3 miles) ⓘHighway 50 roadcut, Texas Creek Area, Fremont County, Colorado, USA
10.7km (6.6 miles) ⓘChief lithium pegmatite, Texas Creek Area, Fremont County, Colorado, USA
References
Hanley, J.B., Heinrich, E.W., Page, L.R. (1950) Pegmatite investigations in Colorado, Wyoming, and Utah, 1942-1944. Professional Paper 227. US Geological Survey doi:10.3133/pp227
Eckel, Edwin Butt; Cobban, Robert R.; Mosburg, Shirley K.; Foord, Eugene E. (1997) Minerals of Colorado. Fulcrum Publishing. 676pp.pp.14-15
 
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: October 21, 2026 17:46:57
Go to top of page