Cosumnes Copper Mine, Fair Play, Fairplay Mining District, El Dorado County, California, USAi
| Regional Level Types | |
|---|---|
| Cosumnes Copper Mine | Mine (Inactive) |
| Fair Play | Unincorporated Community |
| Fairplay Mining District | Mining District |
| El Dorado County | County |
| California | State |
| USA | Country |
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Latitude & Longitude (WGS84):
38° 36' 24'' North , 120° 36' 24'' West
Latitude & Longitude (decimal):
Type:
Mine (Inactive) - last checked 2022
Köppen climate type:
Nearest Settlements:
| Place | Population | Distance |
|---|---|---|
| River Pines | 379 (2011) | 13.7km |
| Camino | 1,750 (2011) | 15.8km |
| Fiddletown | 235 (2011) | 17.3km |
| Pollock Pines | 6,871 (2017) | 17.3km |
| Volcano | 115 (2017) | 18.3km |
Nearest Clubs:
Local clubs are the best way to get access to collecting localities
Local clubs are the best way to get access to collecting localities
| Club | Location | Distance |
|---|---|---|
| El Dorado County Mineral and Gem Society | Placerville, California | 22km |
| Gold Country Treasure Seekers | Placerville, California | 22km |
| Amador County Gem & Mineral Society | Sutter Creek, California | 29km |
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.
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 ElementsDetailed Mineral List:
| ⓘ Axinite-(Mn) Formula: Ca2Mn2+Al2BSi4O15(OH) Colour: Brown Description: Occurs as small clear crystals on epidote. References: Schaller, W. T. (1911) Mineralogical notes, series 1. Bulletin 490. US Geological Survey 109 pp. doi:10.3133/b490 pp.37-47 - (Axinite from California) |
| ⓘ 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 References: |
| ⓘ 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. References: |
| ⓘ 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(C2+4C3+)(AlSi7O22)W2 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 References: |
| ⓘ Native Gold Formula: Au |
| ⓘ Native Silver Formula: Ag |
| ⓘ Orthoclase Formula: K(AlSi3O8) |
| ⓘ Powellite Formula: Ca(MoO4) References: |
| ⓘ Pyrophyllite Formula: Al2Si4O10(OH)2 References: |
| ⓘ Quartz Formula: SiO2 |
| ⓘ Stibnite Formula: Sb2S3 |
List of minerals arranged by Strunz 10th Edition classification
| Group 1 - Elements | |||
|---|---|---|---|
| ⓘ | Native Copper | 1.AA.05 | Cu |
| ⓘ | Native Gold | 1.AA.05 | Au |
| ⓘ | Native Silver | 1.AA.05 | Ag |
| Group 2 - Sulphides and Sulfosalts | |||
| ⓘ | Chalcocite | 2.BA.05 | Cu2S |
| ⓘ | Bornite | 2.BA.15 | Cu5FeS4 |
| ⓘ | Chalcopyrite | 2.CB.10a | CuFeS2 |
| ⓘ | Stibnite | 2.DB.05 | Sb2S3 |
| ⓘ | Molybdenite | 2.EA.30 | MoS2 |
| Group 4 - Oxides and Hydroxides | |||
| ⓘ | Magnetite | 4.BB.05 | Fe2+Fe3+2O4 |
| ⓘ | Corundum | 4.CB.05 | Al2O3 |
| ⓘ | Quartz | 4.DA.05 | SiO2 |
| Group 5 - Nitrates and Carbonates | |||
| ⓘ | Calcite | 5.AB.05 | CaCO3 |
| ⓘ | Azurite | 5.BA.05 | Cu3(CO3)2(OH)2 |
| ⓘ | Malachite | 5.BA.10 | Cu2(CO3)(OH)2 |
| Group 7 - Sulphates, Chromates, Molybdates and Tungstates | |||
| ⓘ | Powellite | 7.GA.05 | Ca(MoO4) |
| ⓘ | Ferrimolybdite | 7.GB.30 | Fe2(MoO4)3 · nH2O |
| Group 9 - Silicates | |||
| ⓘ | Grossular | 9.AD.25 | Ca3Al2(SiO4)3 |
| ⓘ | Axinite-(Mn) | 9.BD.20 | Ca2Mn2+Al2BSi4O15(OH) |
| ⓘ | Epidote | 9.BG.05a | (CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH) |
| ⓘ | Diopside | 9.DA.15 | CaMgSi2O6 |
| ⓘ | Pyrophyllite | 9.EC.10 | Al2Si4O10(OH)2 |
| ⓘ | Orthoclase | 9.FA.30 | K(AlSi3O8) |
| Unclassified | |||
| ⓘ | 'Limonite' | - | |
| ⓘ | 'Hornblende Root Name Group' | - | ◻Ca2(C2+4C3+)(AlSi7O22)W2 |
| ⓘ | 'Garnet Group' | - | X3Z2(SiO4)3 |
List of minerals for each chemical element
| H | Hydrogen | |
|---|---|---|
| H | ⓘ Azurite | Cu3(CO3)2(OH)2 |
| H | ⓘ Epidote | (CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH) |
| H | ⓘ Ferrimolybdite | Fe2(MoO4)3 · nH2O |
| H | ⓘ Axinite-(Mn) | Ca2Mn2+Al2BSi4O15(OH) |
| H | ⓘ Malachite | Cu2(CO3)(OH)2 |
| H | ⓘ Pyrophyllite | Al2Si4O10(OH)2 |
| B | Boron | |
| B | ⓘ Axinite-(Mn) | Ca2Mn2+Al2BSi4O15(OH) |
| C | Carbon | |
| C | ⓘ Azurite | Cu3(CO3)2(OH)2 |
| C | ⓘ Calcite | CaCO3 |
| C | ⓘ Malachite | Cu2(CO3)(OH)2 |
| O | Oxygen | |
| O | ⓘ Azurite | Cu3(CO3)2(OH)2 |
| O | ⓘ Calcite | CaCO3 |
| O | ⓘ Corundum | Al2O3 |
| O | ⓘ Diopside | CaMgSi2O6 |
| O | ⓘ Epidote | (CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH) |
| O | ⓘ Ferrimolybdite | Fe2(MoO4)3 · nH2O |
| O | ⓘ Grossular | Ca3Al2(SiO4)3 |
| O | ⓘ Axinite-(Mn) | Ca2Mn2+Al2BSi4O15(OH) |
| O | ⓘ Magnetite | Fe2+Fe23+O4 |
| O | ⓘ Malachite | Cu2(CO3)(OH)2 |
| O | ⓘ Orthoclase | K(AlSi3O8) |
| O | ⓘ Powellite | Ca(MoO4) |
| O | ⓘ Pyrophyllite | Al2Si4O10(OH)2 |
| O | ⓘ Quartz | SiO2 |
| O | ⓘ Hornblende Root Name Group | ◻Ca2(C42+C3+)(AlSi7O22)W2 |
| O | ⓘ Garnet Group | X3Z2(SiO4)3 |
| Mg | Magnesium | |
| Mg | ⓘ Diopside | CaMgSi2O6 |
| Al | Aluminium | |
| Al | ⓘ Corundum | Al2O3 |
| Al | ⓘ Epidote | (CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH) |
| Al | ⓘ Grossular | Ca3Al2(SiO4)3 |
| Al | ⓘ Axinite-(Mn) | Ca2Mn2+Al2BSi4O15(OH) |
| Al | ⓘ Orthoclase | K(AlSi3O8) |
| Al | ⓘ Pyrophyllite | Al2Si4O10(OH)2 |
| Al | ⓘ Hornblende Root Name Group | ◻Ca2(C42+C3+)(AlSi7O22)W2 |
| Si | Silicon | |
| Si | ⓘ Diopside | CaMgSi2O6 |
| Si | ⓘ Epidote | (CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH) |
| Si | ⓘ Grossular | Ca3Al2(SiO4)3 |
| Si | ⓘ Axinite-(Mn) | Ca2Mn2+Al2BSi4O15(OH) |
| Si | ⓘ Orthoclase | K(AlSi3O8) |
| Si | ⓘ Pyrophyllite | Al2Si4O10(OH)2 |
| Si | ⓘ Quartz | SiO2 |
| Si | ⓘ Hornblende Root Name Group | ◻Ca2(C42+C3+)(AlSi7O22)W2 |
| Si | ⓘ Garnet Group | X3Z2(SiO4)3 |
| S | Sulfur | |
| S | ⓘ Bornite | Cu5FeS4 |
| S | ⓘ Chalcopyrite | CuFeS2 |
| S | ⓘ Chalcocite | Cu2S |
| S | ⓘ Molybdenite | MoS2 |
| S | ⓘ Stibnite | Sb2S3 |
| K | Potassium | |
| K | ⓘ Orthoclase | K(AlSi3O8) |
| Ca | Calcium | |
| Ca | ⓘ Calcite | CaCO3 |
| Ca | ⓘ Diopside | CaMgSi2O6 |
| Ca | ⓘ Epidote | (CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH) |
| Ca | ⓘ Grossular | Ca3Al2(SiO4)3 |
| Ca | ⓘ Axinite-(Mn) | Ca2Mn2+Al2BSi4O15(OH) |
| Ca | ⓘ Powellite | Ca(MoO4) |
| Ca | ⓘ Hornblende Root Name Group | ◻Ca2(C42+C3+)(AlSi7O22)W2 |
| Mn | Manganese | |
| Mn | ⓘ Axinite-(Mn) | Ca2Mn2+Al2BSi4O15(OH) |
| Fe | Iron | |
| Fe | ⓘ Bornite | Cu5FeS4 |
| Fe | ⓘ Chalcopyrite | CuFeS2 |
| Fe | ⓘ Epidote | (CaCa)(AlAlFe3+)O[Si2O7][SiO4](OH) |
| Fe | ⓘ Ferrimolybdite | Fe2(MoO4)3 · nH2O |
| Fe | ⓘ Magnetite | Fe2+Fe23+O4 |
| Cu | Copper | |
| Cu | ⓘ Azurite | Cu3(CO3)2(OH)2 |
| Cu | ⓘ Bornite | Cu5FeS4 |
| Cu | ⓘ Chalcopyrite | CuFeS2 |
| Cu | ⓘ Chalcocite | Cu2S |
| Cu | ⓘ Native Copper | Cu |
| Cu | ⓘ Malachite | Cu2(CO3)(OH)2 |
| Mo | Molybdenum | |
| Mo | ⓘ Ferrimolybdite | Fe2(MoO4)3 · nH2O |
| Mo | ⓘ Molybdenite | MoS2 |
| Mo | ⓘ Powellite | Ca(MoO4) |
| Ag | Silver | |
| Ag | ⓘ Native Silver | Ag |
| Sb | Antimony | |
| Sb | ⓘ Stibnite | Sb2S3 |
| Au | Gold | |
| Au | ⓘ Native Gold | Au |
Other Databases
| Link to USGS MRDS: | 10037064 |
|---|
Other Regions, Features and Areas containing this locality
North AmericaContinent
North America PlateTectonic Plate
- Shoofly-Olds Ferry DomainDomain
- Sierra Nevada BatholithVolcanic Arc
USA
- Sierra NevadaMountain Range
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References
(n.d.) Minerals Availability System (MAS), U.S. Bureau of Mines.file #0060170952
Aubury, Lewis E. (1905) The Copper Resources of California. Bulletin 23. California State Mining Bureau p.180
(1908, September) The Copper Resources of California. Bulletin 50. California State Mining Bureaup.213
Cosumnes Copper Mine, Fair Play, Fairplay Mining District, El Dorado County, California, USA