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Magnolia Mining District, Boulder County, Colorado, USAi
Regional Level Types
Magnolia Mining DistrictMining District
Boulder CountyCounty
ColoradoState
USACountry

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Mindat Locality ID:
24262
Long-form identifier:
mindat:1:2:24262:7
GUID (UUID V4):
0


The Magnolia mining district lies, about 5 miles due west of Boulder and about a mile south of Middle Boulder Creek. The district is about 1,400 feet above the valley bottom.

Most of the productive veins crop out in an area of less than a square mile and the outcrops range in altitude from approximately 7,000 feet at the Graphic vein to about 7,700 feet at the Kekionga shaft a mile to the southwest.

Gold-telluride ore was found on the Magnolia vein in 1875 and during the next 2 years nearly all the veins now known in the district were discovered. Because of the high tenor of the ore and its erratic distribution in rich pockets, company mining and milling by absentee landlords has seldom been successful, and the district does not have a large output on record.

All the ore deposits in the Magnolia district are fissure fillings; mineralization has been chiefly of the gold-tel1urille type but some tungsten ore has been mined. Gangue minerals are present in only minor quantity and consist of little but light-colored to dark-colored varieties of extremely fine grained quartz "horn".

The district is noted for the variety of telluride minerals found and for the unusual association of gold tellurides with tungsten, molybdenum, and vanadium minerals.




Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Commodity List

This is a list of exploitable or exploited mineral commodities recorded from this region.


Mineral List

Mineral list contains entries from the region specified including sub-localities

38 valid minerals. 3 (TL) - type locality of valid minerals.

Rock Types Recorded


Rock list contains entries from the region specified including sub-localities

Select Rock List Type

Alphabetical List Tree Diagram

Detailed Mineral List:

ⓘ Allanite-(Ce)
Formula: (CaCe)(AlAlFe2+)O[Si2O7][SiO4](OH)
ⓘ Altaite
Formula: PbTe
ⓘ Alunite
Formula: KAl3(SO4)2(OH)6
ⓘ Calaverite
Formula: AuTe2
Localities: Reported from at least 6 localities in this region.
ⓘ Calcite
Formula: CaCO3
ⓘ Calomel
Formula: [Hg2]2+Cl2
ⓘ Chalcopyrite
Formula: CuFeS2
ⓘ 'Chlorite Group'
ⓘ Coloradoite (TL)
Formula: HgTe
Description: Closely intermixed with native tellurium and quartz. The type description of coloradoite was based on impure specimens from the Keystone and Mountain Lion mines in the Magnolia district and from the Smuggler mine in the Balarat district.
ⓘ Empressite
Formula: AgTe
ⓘ Epidote
Formula: (CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
ⓘ 'Fayalite-Forsterite Series'
ⓘ 'Feldspar Group'
ⓘ Ferberite
Formula: FeWO4
ⓘ Fluorite
Formula: CaF2
ⓘ 'Garnet Group'
Formula: X3Z2(SiO4)3
ⓘ Goethite
Formula: Fe3+O(OH)
ⓘ Hessite
Formula: Ag2Te
ⓘ Hübnerite
Formula: MnWO4
ⓘ Ilmenite
Formula: Fe2+TiO3
ⓘ Ilmenite var. Picrotitanite
Formula: Fe2+TiO3
ⓘ Iodargyrite
Formula: AgI
ⓘ Keystoneite (TL)
Formula: Mg0.5Ni2+Fe3+(Te4+O3)3 · 4.5H2O
Description: Golden yellow. Admantine luster. Radiating sprays & parallel growth aggregates of hexagonal, aciciular xls. Ave. size of xls: 0.2 x 0.02 x 0.02 mm.
ⓘ 'Limonite'
ⓘ Magnolite (TL)
Formula: [Hg2]2+[Te4+O3]
ⓘ Marcasite
Formula: FeS2
ⓘ Melonite
Formula: NiTe2
ⓘ 'Mica Group'
ⓘ Molybdenite
Formula: MoS2
ⓘ Native Gold
Formula: Au
Localities: Reported from at least 17 localities in this region.
ⓘ Native Mercury
Formula: Hg
ⓘ Native Silver
Formula: Ag
ⓘ Native Silver var. Amalgam
Formula: (Ag,Hg)
ⓘ Native Tellurium
Formula: Te
ⓘ Paratellurite
Formula: TeO2
ⓘ Petzite
Formula: Ag3AuTe2
ⓘ Pyrite
Formula: FeS2
ⓘ Pyrrhotite
Formula: Fe1-xS
ⓘ Quartz
Formula: SiO2
Localities: Reported from at least 7 localities in this region.
ⓘ Quartz var. Chalcedony
Formula: SiO2
ⓘ Rickardite
Formula: Cu7Te5
ⓘ Roscoelite
Formula: KV3+2(AlSi3O10)(OH)2
ⓘ 'Serpentine Subgroup'
Formula: D3[Si2O5](OH)4
ⓘ Sphalerite
Formula: ZnS
ⓘ Stibnite
Formula: Sb2S3
ⓘ Sylvanite
Formula: AgAuTe4
Localities: Reported from at least 9 localities in this region.
ⓘ Tellurite
Formula: TeO2
ⓘ Weishanite
Formula: (Au,Ag,Hg)
Description: structural ID confirmed weishanite. these are the best known crystals of weishanite.

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Group 1 - Elements
ⓘNative Silver
var. Amalgam
1.AA.05(Ag,Hg)
ⓘNative Gold1.AA.05Au
ⓘNative Silver1.AA.05Ag
ⓘNative Mercury1.AD.05Hg
ⓘWeishanite1.AD.20a(Au,Ag,Hg)
ⓘNative Tellurium1.CC.10Te
Group 2 - Sulphides and Sulfosalts
ⓘRickardite2.BA.30Cu7Te5
ⓘHessite2.BA.60Ag2Te
ⓘPetzite2.BA.75Ag3AuTe2
ⓘColoradoite (TL)2.CB.05aHgTe
ⓘSphalerite2.CB.05aZnS
ⓘChalcopyrite2.CB.10aCuFeS2
ⓘEmpressite2.CB.80AgTe
ⓘPyrrhotite2.CC.10Fe1-xS
ⓘAltaite2.CD.10PbTe
ⓘStibnite2.DB.05Sb2S3
ⓘSylvanite2.EA.05AgAuTe4
ⓘCalaverite2.EA.10AuTe2
ⓘMelonite2.EA.20NiTe2
ⓘMolybdenite2.EA.30MoS2
ⓘPyrite2.EB.05aFeS2
ⓘMarcasite2.EB.10aFeS2
Group 3 - Halides
ⓘIodargyrite3.AA.10AgI
ⓘCalomel3.AA.30[Hg2]2+Cl2
ⓘFluorite3.AB.25CaF2
Group 4 - Oxides and Hydroxides
ⓘIlmenite4.CB.05Fe2+TiO3
ⓘvar. Picrotitanite4.CB.05Fe2+TiO3
ⓘQuartz
var. Chalcedony
4.DA.05SiO2
ⓘ4.DA.05SiO2
ⓘFerberite4.DB.30FeWO4
ⓘHübnerite4.DB.30MnWO4
ⓘTellurite4.DE.20TeO2
ⓘParatellurite4.DE.25TeO2
ⓘGoethite4.FD.10Fe3+O(OH)
ⓘMagnolite (TL)4.JK.60[Hg2]2+[Te4+O3]
ⓘKeystoneite (TL)4.JM.05Mg0.5Ni2+Fe3+(Te4+O3)3 · 4.5H2O
Group 5 - Nitrates and Carbonates
ⓘCalcite5.AB.05CaCO3
Group 7 - Sulphates, Chromates, Molybdates and Tungstates
ⓘAlunite7.BC.10KAl3(SO4)2(OH)6
Group 9 - Silicates
ⓘEpidote9.BG.05a(CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
ⓘAllanite-(Ce)9.BG.05b(CaCe)(AlAlFe2+)O[Si2O7][SiO4](OH)
ⓘRoscoelite9.EC.15KV3+2(AlSi3O10)(OH)2
Unclassified
ⓘ'Chlorite Group'-
ⓘ'Feldspar Group'-
ⓘ'Limonite'-
ⓘ'Mica Group'-
ⓘ'Fayalite-Forsterite Series'-
ⓘ'Garnet Group'-X3Z2(SiO4)3
ⓘ'Serpentine Subgroup'-D3[Si2O5](OH)4

List of minerals for each chemical element

HHydrogen
Hⓘ Allanite-(Ce)(CaCe)(AlAlFe2+)O[Si2O7][SiO4](OH)
Hⓘ AluniteKAl3(SO4)2(OH)6
Hⓘ Epidote(CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
Hⓘ GoethiteFe3+O(OH)
Hⓘ KeystoneiteMg0.5Ni2+Fe3+(Te4+O3)3 · 4.5H2O
Hⓘ RoscoeliteKV23+(AlSi3O10)(OH)2
Hⓘ Serpentine SubgroupD3[Si2O5](OH)4
CCarbon
Cⓘ CalciteCaCO3
OOxygen
Oⓘ Allanite-(Ce)(CaCe)(AlAlFe2+)O[Si2O7][SiO4](OH)
Oⓘ AluniteKAl3(SO4)2(OH)6
Oⓘ CalciteCaCO3
Oⓘ Quartz var. ChalcedonySiO2
Oⓘ Epidote(CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
Oⓘ FerberiteFeWO4
Oⓘ GoethiteFe3+O(OH)
Oⓘ HübneriteMnWO4
Oⓘ IlmeniteFe2+TiO3
Oⓘ KeystoneiteMg0.5Ni2+Fe3+(Te4+O3)3 · 4.5H2O
Oⓘ Magnolite[Hg2]2+[Te4+O3]
Oⓘ ParatelluriteTeO2
Oⓘ QuartzSiO2
Oⓘ RoscoeliteKV23+(AlSi3O10)(OH)2
Oⓘ TelluriteTeO2
Oⓘ Fayalite-Forsterite Series
Oⓘ Garnet GroupX3Z2(SiO4)3
Oⓘ Serpentine SubgroupD3[Si2O5](OH)4
Oⓘ Ilmenite var. PicrotitaniteFe2+TiO3
FFluorine
Fⓘ FluoriteCaF2
MgMagnesium
Mgⓘ KeystoneiteMg0.5Ni2+Fe3+(Te4+O3)3 · 4.5H2O
Mgⓘ Fayalite-Forsterite Series
AlAluminium
Alⓘ Allanite-(Ce)(CaCe)(AlAlFe2+)O[Si2O7][SiO4](OH)
Alⓘ AluniteKAl3(SO4)2(OH)6
Alⓘ Epidote(CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
Alⓘ RoscoeliteKV23+(AlSi3O10)(OH)2
SiSilicon
Siⓘ Allanite-(Ce)(CaCe)(AlAlFe2+)O[Si2O7][SiO4](OH)
Siⓘ Quartz var. ChalcedonySiO2
Siⓘ Epidote(CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
Siⓘ QuartzSiO2
Siⓘ RoscoeliteKV23+(AlSi3O10)(OH)2
Siⓘ Fayalite-Forsterite Series
Siⓘ Garnet GroupX3Z2(SiO4)3
Siⓘ Serpentine SubgroupD3[Si2O5](OH)4
SSulfur
Sⓘ AluniteKAl3(SO4)2(OH)6
Sⓘ ChalcopyriteCuFeS2
Sⓘ MarcasiteFeS2
Sⓘ MolybdeniteMoS2
Sⓘ PyriteFeS2
Sⓘ PyrrhotiteFe1-xS
Sⓘ SphaleriteZnS
Sⓘ StibniteSb2S3
ClChlorine
Clⓘ Calomel[Hg2]2+Cl2
KPotassium
Kⓘ AluniteKAl3(SO4)2(OH)6
Kⓘ RoscoeliteKV23+(AlSi3O10)(OH)2
CaCalcium
Caⓘ Allanite-(Ce)(CaCe)(AlAlFe2+)O[Si2O7][SiO4](OH)
Caⓘ CalciteCaCO3
Caⓘ Epidote(CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
Caⓘ FluoriteCaF2
TiTitanium
Tiⓘ IlmeniteFe2+TiO3
Tiⓘ Ilmenite var. PicrotitaniteFe2+TiO3
VVanadium
Vⓘ RoscoeliteKV23+(AlSi3O10)(OH)2
MnManganese
Mnⓘ HübneriteMnWO4
FeIron
Feⓘ Allanite-(Ce)(CaCe)(AlAlFe2+)O[Si2O7][SiO4](OH)
Feⓘ ChalcopyriteCuFeS2
Feⓘ Epidote(CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
Feⓘ FerberiteFeWO4
Feⓘ GoethiteFe3+O(OH)
Feⓘ IlmeniteFe2+TiO3
Feⓘ KeystoneiteMg0.5Ni2+Fe3+(Te4+O3)3 · 4.5H2O
Feⓘ MarcasiteFeS2
Feⓘ PyriteFeS2
Feⓘ PyrrhotiteFe1-xS
Feⓘ Fayalite-Forsterite Series
Feⓘ Ilmenite var. PicrotitaniteFe2+TiO3
NiNickel
Niⓘ KeystoneiteMg0.5Ni2+Fe3+(Te4+O3)3 · 4.5H2O
Niⓘ MeloniteNiTe2
CuCopper
Cuⓘ ChalcopyriteCuFeS2
Cuⓘ RickarditeCu7Te5
ZnZinc
Znⓘ SphaleriteZnS
MoMolybdenum
Moⓘ MolybdeniteMoS2
AgSilver
Agⓘ Native Silver var. Amalgam(Ag,Hg)
Agⓘ EmpressiteAgTe
Agⓘ HessiteAg2Te
Agⓘ IodargyriteAgI
Agⓘ PetziteAg3AuTe2
Agⓘ Native SilverAg
Agⓘ SylvaniteAgAuTe4
Agⓘ Weishanite(Au,Ag,Hg)
SbAntimony
Sbⓘ StibniteSb2S3
TeTellurium
Teⓘ AltaitePbTe
Teⓘ CalaveriteAuTe2
Teⓘ ColoradoiteHgTe
Teⓘ EmpressiteAgTe
Teⓘ HessiteAg2Te
Teⓘ KeystoneiteMg0.5Ni2+Fe3+(Te4+O3)3 · 4.5H2O
Teⓘ Magnolite[Hg2]2+[Te4+O3]
Teⓘ MeloniteNiTe2
Teⓘ ParatelluriteTeO2
Teⓘ PetziteAg3AuTe2
Teⓘ RickarditeCu7Te5
Teⓘ SylvaniteAgAuTe4
Teⓘ TelluriteTeO2
Teⓘ Native TelluriumTe
IIodine
Iⓘ IodargyriteAgI
CeCerium
Ceⓘ Allanite-(Ce)(CaCe)(AlAlFe2+)O[Si2O7][SiO4](OH)
WTungsten
Wⓘ FerberiteFeWO4
Wⓘ HübneriteMnWO4
AuGold
Auⓘ CalaveriteAuTe2
Auⓘ Native GoldAu
Auⓘ PetziteAg3AuTe2
Auⓘ SylvaniteAgAuTe4
Auⓘ Weishanite(Au,Ag,Hg)
HgMercury
Hgⓘ Native Silver var. Amalgam(Ag,Hg)
Hgⓘ Calomel[Hg2]2+Cl2
Hgⓘ ColoradoiteHgTe
Hgⓘ Magnolite[Hg2]2+[Te4+O3]
Hgⓘ Native MercuryHg
Hgⓘ Weishanite(Au,Ag,Hg)
PbLead
Pbⓘ AltaitePbTe

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Localities in this Region

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