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⇱ Cosumnes Copper Mine, Fair Play, Fairplay Mining District, El Dorado County, California, USA

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Cosumnes Copper Mine, Fair Play, Fairplay Mining District, El Dorado County, California, USAi
Regional Level Types
Cosumnes Copper MineMine (Inactive)
Fair PlayUnincorporated Community
Fairplay Mining DistrictMining District
El Dorado CountyCounty
CaliforniaState
USACountry

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Latitude & Longitude (WGS84):
38° 36' 24'' North , 120° 36' 24'' West
Latitude & Longitude (decimal):
Type:
Mine (Inactive) - last checked 2022
Nearest Settlements:
PlacePopulationDistance
River Pines379 (2011)13.7km
Camino1,750 (2011)15.8km
Fiddletown235 (2011)17.3km
Pollock Pines6,871 (2017)17.3km
Volcano115 (2017)18.3km
Nearest Clubs:
Local clubs are the best way to get access to collecting localities
ClubLocationDistance
El Dorado County Mineral and Gem SocietyPlacerville, California22km
Gold Country Treasure SeekersPlacerville, California22km
Amador County Gem & Mineral SocietySutter Creek, California29km
Mindat Locality ID:
10363
Long-form identifier:
mindat:1:2:10363:8
GUID (UUID V4):
0
Other/historical names associated with this locality:
Consumnes Copper Mine, Rocky Bar Copper Mine, Rocky Bar Mine


A former Cu-Mo-Au-Ag-Sb-W mine located in the NW¼ sec. 25, T9N, R12E, MDM, about 5 km (3 miles) ENE of Fairplay on the S side of the Middle Fork Cosumnes River (13.5 miles SE of Placerville).

Production was reported but not recorded.

Analytical data results: MoS2 = 0.08-0.83%; Cu = 0.28-3.09%.
A former Au-Pb-Mo-Ag-Cu occurrence/mine located in the SE¼SW¼ sec. 24 & in the NW¼ sec. 25, T9N, R12E, MDM, 1.4 km (0.9 mile) SSW of Coles Station, along the S side of the Middle Fork Cosumnes River (4 miles NW of Fairplay). Operated by Lee Miller (1955). Operated originally in 1850; active around 1896 and during both world wars plus in 1955. MRDS database stated accuracy for this location is 100 meters.

NOTE: Geographic coordinates presented have been adjusted to correspond to the exact location reflected on the topo map.

Mineralization is a vein deposit hosted in granodiorite and limestone. The ore body is 9.14 meters wide. The Cu minerals occur in a contact metamorphic zone. A tactite zone occurs & some of it is radioactive. Other rocks in the area are amphibolite and mica schist. Local rocks include Mesozoic granitic rocks, unit 3 (Sierra Nevada, Death Valley area, Northern Mojave Desert and Transverse Ranges) and/or Paleozoic marine rocks, undivided, unit 4 (Western Sierra Nevada).

Workings include surface and underground openings comprised of a 150 foot crosscut adit, driven westward with drifts running NE & SW. A 30 foot raise was driven just S of the adit-drift intersection. A lower crosscut adit was driven about 40 feet below the main adit. with the 2 levels connected by a winze. There are numerous open cuts above the adit portals.

A small amount of ore was produced from the open cuts during WWII. Reopened early in 1955 and several tons of ore were produced and stockpiled. Three men were working in 1955.

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Mineral List


22 valid minerals.

Detailed Mineral List:

ⓘ Axinite-(Mn)
Formula: Ca2Mn2+Al2BSi4O15(OH)
Colour: Brown
Description: Occurs as small clear crystals on epidote.
ⓘ Azurite
Formula: Cu3(CO3)2(OH)2
ⓘ Bornite
Formula: Cu5FeS4
Description: Occurs as massive material with molybdenite in a coarse pegmatite.
ⓘ Calcite
Formula: CaCO3
Description: Occurs as good crystals.
ⓘ Chalcocite
Formula: Cu2S
ⓘ Chalcopyrite
Formula: CuFeS2
ⓘ Corundum
Formula: Al2O3
References:
MOHs test, fluoresces purple under LW UVIdentified by Ech Noch: Visual Identification, Visual (Fluorescence)
ⓘ Diopside
Formula: CaMgSi2O6
Description: Occurs as fine crystals.
ⓘ Epidote
Formula: (CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
Description: Occurs as large crystals coated by axinite in a coarse vein.
ⓘ Ferrimolybdite
Formula: Fe2(MoO4)3 · nH2O
ⓘ 'Garnet Group'
Formula: X3Z2(SiO4)3
ⓘ Grossular
Formula: Ca3Al2(SiO4)3
Description: Occurs as large crystals.
ⓘ 'Hornblende Root Name Group'
Formula: ◻Ca2(Z2+4Z3+)(AlSi7O22)(OH,F,Cl)2
Colour: Black
Description: Occurs as large cleavage masses.
ⓘ 'Limonite'
References:
ⓘ Magnetite
Formula: Fe2+Fe3+2O4
ⓘ Malachite
Formula: Cu2(CO3)(OH)2
ⓘ Molybdenite
Formula: MoS2
Description: Occurs with massive bornite as foliated plates and crystals to 6 cm diameter in a coarse pegmatite.
ⓘ Native Copper
Formula: Cu
ⓘ Native Gold
Formula: Au
ⓘ Native Silver
Formula: Ag
ⓘ Orthoclase
Formula: K(AlSi3O8)
ⓘ Powellite
Formula: Ca(MoO4)
ⓘ Pyrophyllite
Formula: Al2Si4O10(OH)2
ⓘ Quartz
Formula: SiO2
ⓘ Stibnite
Formula: Sb2S3

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Group 1 - Elements
ⓘNative Copper1.AA.05Cu
ⓘNative Gold1.AA.05Au
ⓘNative Silver1.AA.05Ag
Group 2 - Sulphides and Sulfosalts
ⓘChalcocite2.BA.05Cu2S
ⓘBornite2.BA.15Cu5FeS4
ⓘChalcopyrite2.CB.10aCuFeS2
ⓘStibnite2.DB.05Sb2S3
ⓘMolybdenite2.EA.30MoS2
Group 4 - Oxides and Hydroxides
ⓘMagnetite4.BB.05Fe2+Fe3+2O4
ⓘCorundum4.CB.05Al2O3
ⓘQuartz4.DA.05SiO2
Group 5 - Nitrates and Carbonates
ⓘCalcite5.AB.05CaCO3
ⓘAzurite5.BA.05Cu3(CO3)2(OH)2
ⓘMalachite5.BA.10Cu2(CO3)(OH)2
Group 7 - Sulphates, Chromates, Molybdates and Tungstates
ⓘPowellite7.GA.05Ca(MoO4)
ⓘFerrimolybdite7.GB.30Fe2(MoO4)3 · nH2O
Group 9 - Silicates
ⓘGrossular9.AD.25Ca3Al2(SiO4)3
ⓘAxinite-(Mn)9.BD.20Ca2Mn2+Al2BSi4O15(OH)
ⓘEpidote9.BG.05a(CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
ⓘDiopside9.DA.15CaMgSi2O6
ⓘPyrophyllite9.EC.10Al2Si4O10(OH)2
ⓘOrthoclase9.FA.30K(AlSi3O8)
Unclassified
ⓘ'Limonite'-
ⓘ'Hornblende Root Name Group'-◻Ca2(Z2+4Z3+)(AlSi7O22)(OH,F,Cl)2
ⓘ'Garnet Group'-X3Z2(SiO4)3

List of minerals for each chemical element

HHydrogen
Hⓘ AzuriteCu3(CO3)2(OH)2
Hⓘ Epidote(CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
Hⓘ FerrimolybditeFe2(MoO4)3 · nH2O
Hⓘ Axinite-(Mn)Ca2Mn2+Al2BSi4O15(OH)
Hⓘ MalachiteCu2(CO3)(OH)2
Hⓘ PyrophylliteAl2Si4O10(OH)2
Hⓘ Hornblende Root Name Group◻Ca2(Z42+Z3+)(AlSi7O22)(OH,F,Cl)2
BBoron
Bⓘ Axinite-(Mn)Ca2Mn2+Al2BSi4O15(OH)
CCarbon
Cⓘ AzuriteCu3(CO3)2(OH)2
Cⓘ CalciteCaCO3
Cⓘ MalachiteCu2(CO3)(OH)2
OOxygen
Oⓘ AzuriteCu3(CO3)2(OH)2
Oⓘ CalciteCaCO3
Oⓘ CorundumAl2O3
Oⓘ DiopsideCaMgSi2O6
Oⓘ Epidote(CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
Oⓘ FerrimolybditeFe2(MoO4)3 · nH2O
Oⓘ GrossularCa3Al2(SiO4)3
Oⓘ Axinite-(Mn)Ca2Mn2+Al2BSi4O15(OH)
Oⓘ MagnetiteFe2+Fe23+O4
Oⓘ MalachiteCu2(CO3)(OH)2
Oⓘ OrthoclaseK(AlSi3O8)
Oⓘ PowelliteCa(MoO4)
Oⓘ PyrophylliteAl2Si4O10(OH)2
Oⓘ QuartzSiO2
Oⓘ Hornblende Root Name Group◻Ca2(Z42+Z3+)(AlSi7O22)(OH,F,Cl)2
Oⓘ Garnet GroupX3Z2(SiO4)3
FFluorine
Fⓘ Hornblende Root Name Group◻Ca2(Z42+Z3+)(AlSi7O22)(OH,F,Cl)2
MgMagnesium
Mgⓘ DiopsideCaMgSi2O6
AlAluminium
Alⓘ CorundumAl2O3
Alⓘ Epidote(CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
Alⓘ GrossularCa3Al2(SiO4)3
Alⓘ Axinite-(Mn)Ca2Mn2+Al2BSi4O15(OH)
Alⓘ OrthoclaseK(AlSi3O8)
Alⓘ PyrophylliteAl2Si4O10(OH)2
Alⓘ Hornblende Root Name Group◻Ca2(Z42+Z3+)(AlSi7O22)(OH,F,Cl)2
SiSilicon
Siⓘ DiopsideCaMgSi2O6
Siⓘ Epidote(CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
Siⓘ GrossularCa3Al2(SiO4)3
Siⓘ Axinite-(Mn)Ca2Mn2+Al2BSi4O15(OH)
Siⓘ OrthoclaseK(AlSi3O8)
Siⓘ PyrophylliteAl2Si4O10(OH)2
Siⓘ QuartzSiO2
Siⓘ Hornblende Root Name Group◻Ca2(Z42+Z3+)(AlSi7O22)(OH,F,Cl)2
Siⓘ Garnet GroupX3Z2(SiO4)3
SSulfur
Sⓘ BorniteCu5FeS4
Sⓘ ChalcopyriteCuFeS2
Sⓘ ChalcociteCu2S
Sⓘ MolybdeniteMoS2
Sⓘ StibniteSb2S3
ClChlorine
Clⓘ Hornblende Root Name Group◻Ca2(Z42+Z3+)(AlSi7O22)(OH,F,Cl)2
KPotassium
Kⓘ OrthoclaseK(AlSi3O8)
CaCalcium
Caⓘ CalciteCaCO3
Caⓘ DiopsideCaMgSi2O6
Caⓘ Epidote(CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
Caⓘ GrossularCa3Al2(SiO4)3
Caⓘ Axinite-(Mn)Ca2Mn2+Al2BSi4O15(OH)
Caⓘ PowelliteCa(MoO4)
Caⓘ Hornblende Root Name Group◻Ca2(Z42+Z3+)(AlSi7O22)(OH,F,Cl)2
MnManganese
Mnⓘ Axinite-(Mn)Ca2Mn2+Al2BSi4O15(OH)
FeIron
Feⓘ BorniteCu5FeS4
Feⓘ ChalcopyriteCuFeS2
Feⓘ Epidote(CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH)
Feⓘ FerrimolybditeFe2(MoO4)3 · nH2O
Feⓘ MagnetiteFe2+Fe23+O4
CuCopper
Cuⓘ AzuriteCu3(CO3)2(OH)2
Cuⓘ BorniteCu5FeS4
Cuⓘ ChalcopyriteCuFeS2
Cuⓘ ChalcociteCu2S
Cuⓘ Native CopperCu
Cuⓘ MalachiteCu2(CO3)(OH)2
MoMolybdenum
Moⓘ FerrimolybditeFe2(MoO4)3 · nH2O
Moⓘ MolybdeniteMoS2
Moⓘ PowelliteCa(MoO4)
AgSilver
Agⓘ Native SilverAg
SbAntimony
Sbⓘ StibniteSb2S3
AuGold
Auⓘ Native GoldAu

Other Databases

Link to USGS MRDS:10037064

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