Vote for your favorite mineral in #MinCup26! - Sphalerite vs. Anorthite
Both zinc ore Sphalerite and calcium plagioclase feldspar Anorthite have perfect cleavage that will split cleanly if you hit them with a hammer, but only one can claim a larger split of your votes!
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
Green Mountain Mine (Copper Boy Mine), Grape Creek Mining District (Greenhorn 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 Green Mountain Mine (Copper Boy Mine), Grape Creek Mining District (Greenhorn Mining District), Fremont County, Colorado, USA
Data Identifiers
Mindat Occurrence Record ID:736994
Long-form Identifier:1:3:736994:0
GUID (UUID V4):0
Nearest other occurrences of Biotite
3.3km (2.0 miles) ⓘIron Mountain, Iron Mountain complex, Fremont County, Colorado, USA
4.0km (2.5 miles) ⓘGood News No. 1 Property (Goat Park; Good News Complex), Grape Creek Mining District (Greenhorn Mining District), Fremont County, Colorado, USA
4.1km (2.6 miles) ⓘIron Mountain Mine (Iron Mountain Deposit; Iron Mountain Titaniferous Magnetite Deposit), McClure Mountain Complex, Fremont County, Colorado, USA
4.4km (2.7 miles) ⓘGood News No. 2 Claims (Goat Park), Grape Creek Mining District (Greenhorn Mining District), Fremont County, Colorado, USA
4.8km (3.0 miles) ⓘEl Plomo Mine, Grape Creek Mining District (Greenhorn Mining District), Fremont County, Colorado, USA
6.1km (3.8 miles) ⓘHorseshoe Mine (School Section Deposit), Grape Creek Mining District (Greenhorn Mining District), Fremont County, Colorado, USA
6.4km (4.0 miles) ⓘMcClure Gulch carbonatite, McClure Mountain Complex, Fremont County, Colorado, USA
6.7km (4.2 miles) ⓘJoker Mine (Rocky Mountain Boy Claims Patented Claims), Grape Creek Mining District (Greenhorn Mining District), Fremont County, Colorado, USA
8.1km (5.0 miles) ⓘDawson Gold project, Fremont County, Colorado, USA
8.9km (5.5 miles) ⓘDawson Mountain - Surprise Group (Unpatented Claims: Sam 1-15 1977 Part; Copper Boy 1902), Grape Creek Mining District (Greenhorn Mining District), Fremont County, Colorado, USA
References
The Canadian Mineralogist Vol. 43, pp. 601-622 (2005)
Spry, Paul G.; McFadden, Scott; Teale, Graham S.; Alers, Brian; Shallow, John M.; Glenn, Justin M. (2022) Nodular sillimanite rocks as field indicators to metamorphosed massive sulfide deposits. Ore Geology Reviews, 141. 104632 doi:10.1016/j.oregeorev.2021.104632
Berke, Edward H., Spry, Paul G., Heimann, Adriana, Teale, Graham S., Johnson, Benjamin, von der Handt, Anette, Alers, Brian, Shallow, John M. (2023) The genesis of metamorphosed Paleoproterozoic massive sulphide occurrences in central Colorado: geological, mineralogical and sulphur isotope constraints. Geological Magazine, 160 (7) 1345-1375 doi:10.1017/s0016756823000407
 
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 3, 2026 17:00:45
Go to top of page