Vote for your favorite mineral in #MinCup26! - Cuprite vs. Halite
While externally similar shapes, these two minerals are very different inside.
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

Muscovite from
Etta Mine, Keystone, Keystone Mining District, Pennington County, South Dakota, USA


Locality type:Mine
Classification
Species:Muscovite
Formula:KAl2(AlSi3O10)(OH)2
Comments:Occurs in a lithia pegmatite. Muscovite crystals 3 feet to 4 feet in diameter recorded!
Quality for species:Excellent - world class for species or very significant. (!!)
Confirmation
Validity:Believed Valid
Associated Minerals Based on Photo Data:
Columbite-Tantalite7
Beryl3
Albite3
Data
Mineral Data:Click here to view Muscovite data
Locality Data:Click here to view Etta Mine, Keystone, Keystone Mining District, Pennington County, South Dakota, USA
Data Identifiers
Mindat Occurrence Record ID:64590
Long-form Identifier:1:3:64590:0
GUID (UUID V4):0
Nearest other occurrences of Muscovite
0.4km (0.2 miles) ⓘMonte Carlo Prospect, Keystone Mining District, Pennington County, South Dakota, USA
0.6km (0.3 miles) ⓘExpectation Pegmatite, Keystone Mining District, Pennington County, South Dakota, USA
0.6km (0.4 miles) ⓘNickel Plate Mine, Keystone, Keystone Mining District, Pennington County, South Dakota, USA
1.1km (0.7 miles) ⓘWhite Cap Mine, Keystone, Keystone Mining District, Pennington County, South Dakota, USA
1.1km (0.7 miles) ⓘPeerless Mine, Keystone, Keystone Mining District, Pennington County, South Dakota, USA
1.2km (0.7 miles) ⓘHugo Mine, Keystone, Keystone Mining District, Pennington County, South Dakota, USA
1.2km (0.7 miles) ⓘEdison Mine, Keystone, Keystone Mining District, Pennington County, South Dakota, USA
1.2km (0.7 miles) ⓘDan Patch West Mine, Keystone, Keystone Mining District, Pennington County, South Dakota, USA
1.9km (1.2 miles) ⓘHoly Terror Mine, Keystone Gold Mining District, Pennington County, South Dakota, USA
2.3km (1.5 miles) ⓘPink Elephant Beryl prospect, Keystone Mining District, Pennington County, South Dakota, USA
References
 
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 29, 2026 05:06:31
Go to top of page