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

Nickel Plate Mine, Keystone, Keystone Mining District, Pennington County, South Dakota, USAi
Regional Level Types
Nickel Plate MineMine
KeystoneTown
Keystone Mining DistrictMining District
Pennington CountyCounty
South DakotaState
USACountry

This page is currently not sponsored. Click here to sponsor this page.
PhotosMapsSearch
04521300017272015439905.jpg
Open Cut at the Nickel Plate Mine

Nickel Plate Mine, Keystone, Keystone Mining District, Pennington County, South Dakota, USA
01019150017272015459319.jpg
Digging through the dumps at the Nickel Plate Mine

Nickel Plate Mine, Keystone, Keystone Mining District, Pennington County, South Dakota, USA
05693840017272015465573.jpg
Arrojadite-(KFe), etc.

Nickel Plate Mine, Keystone, Keystone Mining District, Pennington County, South Dakota, USA
04521300017272015439905.jpg
Open Cut at the Nickel Plate Mine

Nickel Plate Mine, Keystone, Keystone Mining District, Pennington County, South Dakota, USA
01019150017272015459319.jpg
Digging through the dumps at the Nickel Plate Mine

Nickel Plate Mine, Keystone, Keystone Mining District, Pennington County, South Dakota, USA
06657240017271921097924.jpg
Arrojadite-(KFe), etc.

Nickel Plate Mine, Keystone, Keystone Mining District, Pennington County, South Dakota, USA
07295340017272015605549.jpg
Open Cut at the Nickel Plate Mine

Nickel Plate Mine, Keystone, Keystone Mining District, Pennington County, South Dakota, USA
01019150017272015459319.jpg
Digging through the dumps at the Nickel Plate Mine

Nickel Plate Mine, Keystone, Keystone Mining District, Pennington County, South Dakota, USA
Latitude & Longitude (WGS84):
43° 53' 0'' North , 103° 24' 45'' West
Latitude & Longitude (decimal):
43.88361,-103.41250
GeoHash:
G#: 9xy3wuc2d
GRN:
N30W54
Type:
Mine
Köppen climate type:
BSk : Cold semi-arid (steppe) climate
Nearest Settlements:
PlacePopulationDistance
Keystone343 (2017)1.4km
Hill City995 (2017)14.1km
Colonial Pine Hills2,493 (2017)15.8km
Hermosa392 (2017)18.4km
Custer1,952 (2017)19.8km
Nearest Clubs:
Local clubs are the best way to get access to collecting localities
ClubLocationDistance
Western Dakota Gem & Mineral SocietyRapid City, South Dakota26km
Mindat Locality ID:
4118
Long-form identifier:
mindat:1:2:4118:1
GUID (UUID V4):
0


A tin mine in pegmatite.
200 yards east of Keystone Cemetery.

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Mineral List


15 valid minerals. 1 (TL) - type locality of valid minerals.

Detailed Mineral List:

ⓘ Albite
Formula: Na(AlSi3O8)
ⓘ Arrojadite-(KFe) (TL)
Formula: (KNa)(Fe2+◻)Ca(Na2◻)Fe2+13Al(PO4)11(PO3OH)(OH)2
Type Locality:
Description: As large cleavable masses to 15 cm in a granitic pegmatite associated with quartz, graftonite, sphalerite, cassiterite, beryl, muscovite and spodumene. The material is dark green and translucent. This was the first arrojadite found, but it was not described well and given the name headdenite after the American mineralogist William Headden (1850-1932) who first described the mineral.
ⓘ Arsenopyrite
Formula: FeAsS
ⓘ Beryl
Formula: Be3Al2(Si6O18)
ⓘ Cassiterite
Formula: SnO2
✪ 'Columbite-(Fe)-Columbite-(Mn) Series'
Habit: flat prismatic
Colour: black, irridescent tarnish
Fluorescence: none
Description: Typical flattened prismatic crystals, embedded in albite or microcline matrix, in single crystals but mostly subparallel groups; Fe-end member
ⓘ Dickinsonite-(KMnNa)
Formula: (KNa)(Mn2+◻)Ca(Na2Na)Mn2+13Al(PO4)11(PO4)(OH)2
ⓘ Graftonite
Formula: Fe2+Fe2+2(PO4)2
ⓘ Microcline
Formula: K(AlSi3O8)
ⓘ Molybdenite
Formula: MoS2
ⓘ Muscovite
Formula: KAl2(AlSi3O10)(OH)2
ⓘ Quartz
Formula: SiO2
ⓘ Sphalerite
Formula: ZnS
ⓘ Spodumene
Formula: LiAlSi2O6
ⓘ 'Tapiolite'
Formula: (Fe,Mn)(Ta,Nb)2O6
Habit: blocky, equant
Colour: black
Fluorescence: none
ⓘ Triphylite
Formula: LiFe2+PO4
References:
Dana 6: 1088.
ⓘ Wyllieite
Formula: (Na,Ca,Mn)(Mn,Fe)(Fe,Mg)Al(PO4)3

List of minerals arranged by Strunz 10th Edition classification

Group 2 - Sulphides and Sulfosalts
ⓘSphalerite2.CB.05aZnS
ⓘMolybdenite2.EA.30MoS2
ⓘArsenopyrite2.EB.20FeAsS
Group 4 - Oxides and Hydroxides
ⓘQuartz4.DA.05SiO2
ⓘCassiterite4.DB.05SnO2
Group 8 - Phosphates, Arsenates and Vanadates
ⓘTriphylite8.AB.10LiFe2+PO4
ⓘGraftonite8.AB.20Fe2+Fe2+2(PO4)2
ⓘWyllieite8.AC.15(Na,Ca,Mn)(Mn,Fe)(Fe,Mg)Al(PO4)3
ⓘArrojadite-(KFe) (TL)8.BF.05(KNa)(Fe2+◻)Ca(Na2◻)Fe2+13Al(PO4)11(PO3OH)(OH)2
ⓘDickinsonite-(KMnNa)8.BF.05(KNa)(Mn2+◻)Ca(Na2Na)Mn2+13Al(PO4)11(PO4)(OH)2
Group 9 - Silicates
ⓘBeryl9.CJ.05Be3Al2(Si6O18)
ⓘSpodumene9.DA.30LiAlSi2O6
ⓘMuscovite9.EC.15KAl2(AlSi3O10)(OH)2
ⓘMicrocline9.FA.30K(AlSi3O8)
ⓘAlbite9.FA.35Na(AlSi3O8)
Unclassified
ⓘ'Tapiolite'-(Fe,Mn)(Ta,Nb)2O6
ⓘ'Columbite-(Fe)-Columbite-(Mn) Series'-

List of minerals for each chemical element

HHydrogen
Hⓘ Arrojadite-(KFe)(KNa)(Fe2+◻)Ca(Na2◻)Fe132+Al(PO4)11(PO3OH)(OH)2
Hⓘ Dickinsonite-(KMnNa)(KNa)(Mn2+◻)Ca(Na2Na)Mn132+Al(PO4)11(PO4)(OH)2
Hⓘ MuscoviteKAl2(AlSi3O10)(OH)2
LiLithium
Liⓘ SpodumeneLiAlSi2O6
Liⓘ TriphyliteLiFe2+PO4
BeBeryllium
Beⓘ BerylBe3Al2(Si6O18)
OOxygen
Oⓘ AlbiteNa(AlSi3O8)
Oⓘ Arrojadite-(KFe)(KNa)(Fe2+◻)Ca(Na2◻)Fe132+Al(PO4)11(PO3OH)(OH)2
Oⓘ BerylBe3Al2(Si6O18)
Oⓘ CassiteriteSnO2
Oⓘ Dickinsonite-(KMnNa)(KNa)(Mn2+◻)Ca(Na2Na)Mn132+Al(PO4)11(PO4)(OH)2
Oⓘ GraftoniteFe2+Fe22+(PO4)2
Oⓘ MicroclineK(AlSi3O8)
Oⓘ MuscoviteKAl2(AlSi3O10)(OH)2
Oⓘ QuartzSiO2
Oⓘ SpodumeneLiAlSi2O6
Oⓘ Tapiolite(Fe,Mn)(Ta,Nb)2O6
Oⓘ TriphyliteLiFe2+PO4
Oⓘ Wyllieite(Na,Ca,Mn)(Mn,Fe)(Fe,Mg)Al(PO4)3
Oⓘ Columbite-(Fe)-Columbite-(Mn) Series
NaSodium
Naⓘ AlbiteNa(AlSi3O8)
Naⓘ Arrojadite-(KFe)(KNa)(Fe2+◻)Ca(Na2◻)Fe132+Al(PO4)11(PO3OH)(OH)2
Naⓘ Dickinsonite-(KMnNa)(KNa)(Mn2+◻)Ca(Na2Na)Mn132+Al(PO4)11(PO4)(OH)2
Naⓘ Wyllieite(Na,Ca,Mn)(Mn,Fe)(Fe,Mg)Al(PO4)3
MgMagnesium
Mgⓘ Wyllieite(Na,Ca,Mn)(Mn,Fe)(Fe,Mg)Al(PO4)3
AlAluminium
Alⓘ AlbiteNa(AlSi3O8)
Alⓘ Arrojadite-(KFe)(KNa)(Fe2+◻)Ca(Na2◻)Fe132+Al(PO4)11(PO3OH)(OH)2
Alⓘ BerylBe3Al2(Si6O18)
Alⓘ Dickinsonite-(KMnNa)(KNa)(Mn2+◻)Ca(Na2Na)Mn132+Al(PO4)11(PO4)(OH)2
Alⓘ MicroclineK(AlSi3O8)
Alⓘ MuscoviteKAl2(AlSi3O10)(OH)2
Alⓘ SpodumeneLiAlSi2O6
Alⓘ Wyllieite(Na,Ca,Mn)(Mn,Fe)(Fe,Mg)Al(PO4)3
SiSilicon
Siⓘ AlbiteNa(AlSi3O8)
Siⓘ BerylBe3Al2(Si6O18)
Siⓘ MicroclineK(AlSi3O8)
Siⓘ MuscoviteKAl2(AlSi3O10)(OH)2
Siⓘ QuartzSiO2
Siⓘ SpodumeneLiAlSi2O6
PPhosphorus
Pⓘ Arrojadite-(KFe)(KNa)(Fe2+◻)Ca(Na2◻)Fe132+Al(PO4)11(PO3OH)(OH)2
Pⓘ Dickinsonite-(KMnNa)(KNa)(Mn2+◻)Ca(Na2Na)Mn132+Al(PO4)11(PO4)(OH)2
Pⓘ GraftoniteFe2+Fe22+(PO4)2
Pⓘ TriphyliteLiFe2+PO4
Pⓘ Wyllieite(Na,Ca,Mn)(Mn,Fe)(Fe,Mg)Al(PO4)3
SSulfur
Sⓘ ArsenopyriteFeAsS
Sⓘ MolybdeniteMoS2
Sⓘ SphaleriteZnS
KPotassium
Kⓘ Arrojadite-(KFe)(KNa)(Fe2+◻)Ca(Na2◻)Fe132+Al(PO4)11(PO3OH)(OH)2
Kⓘ Dickinsonite-(KMnNa)(KNa)(Mn2+◻)Ca(Na2Na)Mn132+Al(PO4)11(PO4)(OH)2
Kⓘ MicroclineK(AlSi3O8)
Kⓘ MuscoviteKAl2(AlSi3O10)(OH)2
CaCalcium
Caⓘ Arrojadite-(KFe)(KNa)(Fe2+◻)Ca(Na2◻)Fe132+Al(PO4)11(PO3OH)(OH)2
Caⓘ Dickinsonite-(KMnNa)(KNa)(Mn2+◻)Ca(Na2Na)Mn132+Al(PO4)11(PO4)(OH)2
Caⓘ Wyllieite(Na,Ca,Mn)(Mn,Fe)(Fe,Mg)Al(PO4)3
MnManganese
Mnⓘ Dickinsonite-(KMnNa)(KNa)(Mn2+◻)Ca(Na2Na)Mn132+Al(PO4)11(PO4)(OH)2
Mnⓘ Tapiolite(Fe,Mn)(Ta,Nb)2O6
Mnⓘ Wyllieite(Na,Ca,Mn)(Mn,Fe)(Fe,Mg)Al(PO4)3
Mnⓘ Columbite-(Fe)-Columbite-(Mn) Series
FeIron
Feⓘ ArsenopyriteFeAsS
Feⓘ Arrojadite-(KFe)(KNa)(Fe2+◻)Ca(Na2◻)Fe132+Al(PO4)11(PO3OH)(OH)2
Feⓘ GraftoniteFe2+Fe22+(PO4)2
Feⓘ Tapiolite(Fe,Mn)(Ta,Nb)2O6
Feⓘ TriphyliteLiFe2+PO4
Feⓘ Wyllieite(Na,Ca,Mn)(Mn,Fe)(Fe,Mg)Al(PO4)3
Feⓘ Columbite-(Fe)-Columbite-(Mn) Series
ZnZinc
Znⓘ SphaleriteZnS
AsArsenic
Asⓘ ArsenopyriteFeAsS
NbNiobium
Nbⓘ Tapiolite(Fe,Mn)(Ta,Nb)2O6
Nbⓘ Columbite-(Fe)-Columbite-(Mn) Series
MoMolybdenum
Moⓘ MolybdeniteMoS2
SnTin
Snⓘ CassiteriteSnO2
TaTantalum
Taⓘ Tapiolite(Fe,Mn)(Ta,Nb)2O6

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.

References

Dana 6: 1088.
Lindberg, Marie Louise (1950) Arrojadite, hühnerkobelite, and graftonite. American Mineralogist, 35 (1-2) 59-76
Daltry, V.D.C., von Knorring, O. (1998) Type-mineralogy of Rwanda with particular reference to the Buranga pegmatite. Geologica Belgica: 1: 9-15. https://popups.uliege.be/1374-8505/index.php?id=1593
Quick NavTopMineral ListOther RegionsReferences
 
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 14:11:30 Page updated: August 12, 2025 02:46:53
Go to top of page