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

Dewey Mine, First Choice Mining District (Garnet Mining District), Granite County, Montana, USAi
Regional Level Types
Dewey MineMine
First Choice Mining District (Garnet Mining District)Mining District
Granite CountyCounty
MontanaState
USACountry

This page is currently not sponsored. Click here to sponsor this page.
PhotosMapsSearch
Latitude & Longitude (WGS84):
46° 49' 36'' North , 113° 20' 35'' West
Latitude & Longitude (decimal):
46.82667,-113.34306
GRN:
N32W56
Type:
Mine
Köppen climate type:
Dfb : Warm-summer humid continental climate
Nearest Settlements:
PlacePopulationDistance
Drummond336 (2017)23.1km
Clinton1,052 (2011)28.8km
Turah306 (2011)37.0km
Seeley Lake1,659 (2011)40.6km
Maxville130 (2011)41.1km
Nearest Clubs:
Local clubs are the best way to get access to collecting localities
ClubLocationDistance
Hellgate Mineral SocietyMissoula, Montana50km
Mindat Locality ID:
161102
Long-form identifier:
mindat:1:2:161102:4
GUID (UUID V4):
0


REF:Deposit:: USGS BULL 660, P. 178-82
Deposit:: MBMG MEM NO 31, P. 32
Commodities (Major) - Gold; (Minor) - Silver, Copper; (Trace) - Antimony, Barium-Barite
Development Status: Past Producer
Structure: Bearmouth Overthrust, Deep Creek Anticline, Garnet Stock

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Commodity List

This is a list of exploitable or exploited mineral commodities recorded at this locality.


Mineral List


6 valid minerals.

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Group 1 - Elements
ⓘNative Gold1.AA.05Au
Group 2 - Sulphides and Sulfosalts
ⓘChalcopyrite2.CB.10aCuFeS2
ⓘPyrite2.EB.05aFeS2
ⓘ'Tetrahedrite Subgroup'2.GB.05Cu6(Cu4C2+2)Sb4S12S
Group 4 - Oxides and Hydroxides
ⓘQuartz4.DA.05SiO2
Group 7 - Sulphates, Chromates, Molybdates and Tungstates
ⓘBaryte7.AD.35BaSO4
Group 9 - Silicates
ⓘMuscovite9.EC.15KAl2(AlSi3O10)(OH)2
ⓘvar. Sericite9.EC.15KAl2(AlSi3O10)(OH)2
Unclassified
ⓘ'Limonite'-

List of minerals for each chemical element

HHydrogen
Hⓘ MuscoviteKAl2(AlSi3O10)(OH)2
Hⓘ Muscovite var. SericiteKAl2(AlSi3O10)(OH)2
OOxygen
Oⓘ BaryteBaSO4
Oⓘ MuscoviteKAl2(AlSi3O10)(OH)2
Oⓘ QuartzSiO2
Oⓘ Muscovite var. SericiteKAl2(AlSi3O10)(OH)2
AlAluminium
Alⓘ MuscoviteKAl2(AlSi3O10)(OH)2
Alⓘ Muscovite var. SericiteKAl2(AlSi3O10)(OH)2
SiSilicon
Siⓘ MuscoviteKAl2(AlSi3O10)(OH)2
Siⓘ QuartzSiO2
Siⓘ Muscovite var. SericiteKAl2(AlSi3O10)(OH)2
SSulfur
Sⓘ BaryteBaSO4
Sⓘ ChalcopyriteCuFeS2
Sⓘ PyriteFeS2
Sⓘ Tetrahedrite SubgroupCu6(Cu4C22+)Sb4S12S
KPotassium
Kⓘ MuscoviteKAl2(AlSi3O10)(OH)2
Kⓘ Muscovite var. SericiteKAl2(AlSi3O10)(OH)2
FeIron
Feⓘ ChalcopyriteCuFeS2
Feⓘ PyriteFeS2
CuCopper
Cuⓘ ChalcopyriteCuFeS2
Cuⓘ Tetrahedrite SubgroupCu6(Cu4C22+)Sb4S12S
SbAntimony
Sbⓘ Tetrahedrite SubgroupCu6(Cu4C22+)Sb4S12S
BaBarium
Baⓘ BaryteBaSO4
AuGold
Auⓘ Native GoldAu

Other Databases

Link to USGS MRDS:10102019

Other Regions, Features and Areas containing this locality

North AmericaContinent
North America PlateTectonic Plate
USA

This page contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to visit any sites listed in mindat.org without first ensuring that you have the permission of the land and/or mineral rights holders for access and that you are aware of all safety precautions necessary.
Quick NavTopCommoditiesMineral ListOther DatabasesOther Regions
 
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 18:52:16 Page updated: August 28, 2025 13:21:11
Go to top of page