El Dorado Mine (Duffay Mine), Adams Peak, Last Chance Mining District, Plumas County, California, USAi
| Regional Level Types | |
|---|---|
| El Dorado Mine (Duffay Mine) | Mine |
| Adams Peak | Peak |
| Last Chance Mining District | Mining District |
| Plumas County | County |
| California | State |
| USA | Country |
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Latitude & Longitude (WGS84):
39° 53' 54'' North , 120° 8' 17'' West
Latitude & Longitude (decimal):
Type:
Köppen climate type:
Nearest Settlements:
| Place | Population | Distance |
|---|---|---|
| Chilcoot-Vinton | 454 (2011) | 10.2km |
| Doyle | 678 (2011) | 14.7km |
| Beckwourth | 432 (2017) | 22.3km |
| Loyalton | 702 (2017) | 26.2km |
| Patton Village | 702 (2011) | 27.0km |
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 |
|---|---|---|
| Comstock Gold Prospectors | Reno, Nevada | 50km |
| Reno Gem and Mineral Society | Reno, Nevada | 50km |
A former Cu-Pb-Ag mine located in sec. 25, T24N, R16E, MDM, 3.6 km (2.3 miles) WSW of Adams Peak (coordinates of record), on the W slope of the Diamond Mountains, E of Frenchman Lake and the Little Last Chance Valley, SE of Last Chance Creek, near the Lassen County line (8 miles N of Chilcoot), on National Forest land. Property is comprised of 100 acres. MRDS database stated accuracy for this location is 500 meters. Adjoins the Mohawk Mine on the N.
Mineralization is a fissure vein deposit hosted in granite. The ore body strikes E and dips 55N at a thickness of 1.22 meters and a length of 914.4 meters. Ore emplacement controls included fissures. The deposit consists of a series of quartz fissure veins. Quartz dikes in granite related to either a hydrothermal phase of the magmatic sequence or of pegmatitic-pneumatolitic origin. Local rocks include Mesozoic granitic rocks, unit 3 (Sierra Nevada, Death Valley area, Northern Mojave Desert and Transverse Ranges).
Workings include underground openings with a length of 73.15 meters and an overall depth of 15.24 meters, and comprised of a 60 foot crosscut tunnel (adit ?) which cuts the vein 50 feet below the outcrop. A drift to the E followed the vein for 155 feet. S of the main workings is a vein with a 25 foot tunnel.
Production data are found in: Goodwin, Joseph Grant (1957).
The only recorded production was a small shipment in 1915. It contained 5.56% Pb and 2.23 ounces Ag/ton. In 1909, one car of ore assayed 56% Cu.
Select Mineral List Type
Standard Detailed Gallery Strunz Chemical ElementsDetailed Mineral List:
| ⓘ Brochantite Formula: Cu4(SO4)(OH)6 |
| ⓘ Chalcanthite Formula: CuSO4 · 5H2O |
| ⓘ Chalcocite Formula: Cu2S |
| ⓘ Chalcopyrite Formula: CuFeS2 |
| ⓘ Chrysocolla Formula: Cu2-xAlx(H2-xSi2O5)(OH)4 · nH2O, x < 1 |
| ⓘ Covellite Formula: CuS |
| ⓘ Cuprotungstite Formula: Cu2(WO4)(OH)2 |
| ⓘ Dravite Formula: NaMg3Al6(Si6O18)(BO3)3(OH)3(OH) |
| ⓘ Ferrimolybdite Formula: Fe2(MoO4)3 · nH2O |
| ⓘ Goethite Formula: Fe3+O(OH) |
| ⓘ Hematite Formula: Fe2O3 |
| ⓘ Malachite Formula: Cu2(CO3)(OH)2 |
| ⓘ Melanterite Formula: Fe2+(H2O)6SO4 · H2O |
| ⓘ Molybdenite Formula: MoS2 |
| ⓘ Powellite Formula: Ca(MoO4) |
| ⓘ Pseudomalachite Formula: Cu5(PO4)2(OH)4 |
| ⓘ Pyrite Formula: FeS2 |
| ⓘ Quartz Formula: SiO2 |
| ⓘ Scheelite Formula: Ca(WO4) |
| ⓘ Schorl Formula: NaFe2+3Al6(Si6O18)(BO3)3(OH)3(OH) |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
| Group 2 - Sulphides and Sulfosalts | |||
|---|---|---|---|
| ⓘ | Chalcocite | 2.BA.05 | Cu2S |
| ⓘ | Covellite | 2.CA.05a | CuS |
| ⓘ | Chalcopyrite | 2.CB.10a | CuFeS2 |
| ⓘ | Molybdenite | 2.EA.30 | MoS2 |
| ⓘ | Pyrite | 2.EB.05a | FeS2 |
| Group 4 - Oxides and Hydroxides | |||
| ⓘ | Goethite | 4.00. | Fe3+O(OH) |
| ⓘ | Hematite | 4.CB.05 | Fe2O3 |
| ⓘ | Quartz | 4.DA.05 | SiO2 |
| Group 5 - Nitrates and Carbonates | |||
| ⓘ | Malachite | 5.BA.10 | Cu2(CO3)(OH)2 |
| Group 7 - Sulphates, Chromates, Molybdates and Tungstates | |||
| ⓘ | Brochantite | 7.BB.25 | Cu4(SO4)(OH)6 |
| ⓘ | Chalcanthite | 7.CB.20 | CuSO4 · 5H2O |
| ⓘ | Melanterite | 7.CB.35 | Fe2+(H2O)6SO4 · H2O |
| ⓘ | Powellite | 7.GA.05 | Ca(MoO4) |
| ⓘ | Scheelite | 7.GA.05 | Ca(WO4) |
| ⓘ | Cuprotungstite | 7.GB.15 | Cu2(WO4)(OH)2 |
| ⓘ | Ferrimolybdite | 7.GB.30 | Fe2(MoO4)3 · nH2O |
| Group 8 - Phosphates, Arsenates and Vanadates | |||
| ⓘ | Pseudomalachite | 8.BD.05 | Cu5(PO4)2(OH)4 |
| Group 9 - Silicates | |||
| ⓘ | Dravite | 9.CK.05 | NaMg3Al6(Si6O18)(BO3)3(OH)3(OH) |
| ⓘ | Schorl | 9.CK.05 | NaFe2+3Al6(Si6O18)(BO3)3(OH)3(OH) |
| ⓘ | Chrysocolla | 9.ED.20 | Cu2-xAlx(H2-xSi2O5)(OH)4 · nH2O, x < 1 |
List of minerals for each chemical element
| H | Hydrogen | |
|---|---|---|
| H | ⓘ Brochantite | Cu4(SO4)(OH)6 |
| H | ⓘ Chalcanthite | CuSO4 · 5H2O |
| H | ⓘ Chrysocolla | Cu2-xAlx(H2-xSi2O5)(OH)4 · nH2O, x < 1 |
| H | ⓘ Cuprotungstite | Cu2(WO4)(OH)2 |
| H | ⓘ Dravite | NaMg3Al6(Si6O18)(BO3)3(OH)3(OH) |
| H | ⓘ Ferrimolybdite | Fe2(MoO4)3 · nH2O |
| H | ⓘ Goethite | Fe3+O(OH) |
| H | ⓘ Malachite | Cu2(CO3)(OH)2 |
| H | ⓘ Melanterite | Fe2+(H2O)6SO4 · H2O |
| H | ⓘ Pseudomalachite | Cu5(PO4)2(OH)4 |
| H | ⓘ Schorl | NaFe32+Al6(Si6O18)(BO3)3(OH)3(OH) |
| B | Boron | |
| B | ⓘ Dravite | NaMg3Al6(Si6O18)(BO3)3(OH)3(OH) |
| B | ⓘ Schorl | NaFe32+Al6(Si6O18)(BO3)3(OH)3(OH) |
| C | Carbon | |
| C | ⓘ Malachite | Cu2(CO3)(OH)2 |
| O | Oxygen | |
| O | ⓘ Brochantite | Cu4(SO4)(OH)6 |
| O | ⓘ Chalcanthite | CuSO4 · 5H2O |
| O | ⓘ Chrysocolla | Cu2-xAlx(H2-xSi2O5)(OH)4 · nH2O, x < 1 |
| O | ⓘ Cuprotungstite | Cu2(WO4)(OH)2 |
| O | ⓘ Dravite | NaMg3Al6(Si6O18)(BO3)3(OH)3(OH) |
| O | ⓘ Ferrimolybdite | Fe2(MoO4)3 · nH2O |
| O | ⓘ Goethite | Fe3+O(OH) |
| O | ⓘ Hematite | Fe2O3 |
| O | ⓘ Malachite | Cu2(CO3)(OH)2 |
| O | ⓘ Melanterite | Fe2+(H2O)6SO4 · H2O |
| O | ⓘ Powellite | Ca(MoO4) |
| O | ⓘ Pseudomalachite | Cu5(PO4)2(OH)4 |
| O | ⓘ Quartz | SiO2 |
| O | ⓘ Scheelite | Ca(WO4) |
| O | ⓘ Schorl | NaFe32+Al6(Si6O18)(BO3)3(OH)3(OH) |
| Na | Sodium | |
| Na | ⓘ Dravite | NaMg3Al6(Si6O18)(BO3)3(OH)3(OH) |
| Na | ⓘ Schorl | NaFe32+Al6(Si6O18)(BO3)3(OH)3(OH) |
| Mg | Magnesium | |
| Mg | ⓘ Dravite | NaMg3Al6(Si6O18)(BO3)3(OH)3(OH) |
| Al | Aluminium | |
| Al | ⓘ Chrysocolla | Cu2-xAlx(H2-xSi2O5)(OH)4 · nH2O, x < 1 |
| Al | ⓘ Dravite | NaMg3Al6(Si6O18)(BO3)3(OH)3(OH) |
| Al | ⓘ Schorl | NaFe32+Al6(Si6O18)(BO3)3(OH)3(OH) |
| Si | Silicon | |
| Si | ⓘ Chrysocolla | Cu2-xAlx(H2-xSi2O5)(OH)4 · nH2O, x < 1 |
| Si | ⓘ Dravite | NaMg3Al6(Si6O18)(BO3)3(OH)3(OH) |
| Si | ⓘ Quartz | SiO2 |
| Si | ⓘ Schorl | NaFe32+Al6(Si6O18)(BO3)3(OH)3(OH) |
| P | Phosphorus | |
| P | ⓘ Pseudomalachite | Cu5(PO4)2(OH)4 |
| S | Sulfur | |
| S | ⓘ Brochantite | Cu4(SO4)(OH)6 |
| S | ⓘ Chalcopyrite | CuFeS2 |
| S | ⓘ Chalcanthite | CuSO4 · 5H2O |
| S | ⓘ Chalcocite | Cu2S |
| S | ⓘ Covellite | CuS |
| S | ⓘ Melanterite | Fe2+(H2O)6SO4 · H2O |
| S | ⓘ Molybdenite | MoS2 |
| S | ⓘ Pyrite | FeS2 |
| Ca | Calcium | |
| Ca | ⓘ Powellite | Ca(MoO4) |
| Ca | ⓘ Scheelite | Ca(WO4) |
| Fe | Iron | |
| Fe | ⓘ Chalcopyrite | CuFeS2 |
| Fe | ⓘ Ferrimolybdite | Fe2(MoO4)3 · nH2O |
| Fe | ⓘ Goethite | Fe3+O(OH) |
| Fe | ⓘ Hematite | Fe2O3 |
| Fe | ⓘ Melanterite | Fe2+(H2O)6SO4 · H2O |
| Fe | ⓘ Pyrite | FeS2 |
| Fe | ⓘ Schorl | NaFe32+Al6(Si6O18)(BO3)3(OH)3(OH) |
| Cu | Copper | |
| Cu | ⓘ Brochantite | Cu4(SO4)(OH)6 |
| Cu | ⓘ Chalcopyrite | CuFeS2 |
| Cu | ⓘ Chalcanthite | CuSO4 · 5H2O |
| Cu | ⓘ Chalcocite | Cu2S |
| Cu | ⓘ Chrysocolla | Cu2-xAlx(H2-xSi2O5)(OH)4 · nH2O, x < 1 |
| Cu | ⓘ Covellite | CuS |
| Cu | ⓘ Cuprotungstite | Cu2(WO4)(OH)2 |
| Cu | ⓘ Malachite | Cu2(CO3)(OH)2 |
| Cu | ⓘ Pseudomalachite | Cu5(PO4)2(OH)4 |
| Mo | Molybdenum | |
| Mo | ⓘ Ferrimolybdite | Fe2(MoO4)3 · nH2O |
| Mo | ⓘ Molybdenite | MoS2 |
| Mo | ⓘ Powellite | Ca(MoO4) |
| W | Tungsten | |
| W | ⓘ Cuprotungstite | Cu2(WO4)(OH)2 |
| W | ⓘ Scheelite | Ca(WO4) |
Other Databases
| Link to USGS MRDS: | 10103003 |
|---|
Other Regions, Features and Areas containing this locality
North AmericaContinent
North America PlateTectonic Plate
- Northern Basin and RangeWide Rift
- Shoofly-Olds Ferry DomainDomain
USA
- California
- Diamond MountainsMountain Range
- Sierra NevadaMountain Range
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References
(n.d.) Minerals Availability System (MAS), U.S. Bureau of Mines.file ID #0060630586
Bramel, Hadley R., Heyl, George R., Cox, Manning W., Ransome, Alfred L., Eric, John H., Wyant, Donald G. (1948) Copper in California. Bulletin 144. California State Mining Bureau p.286
El Dorado Mine, Adams Peak, Last Chance Mining District, Plumas County, California, USA