McCurdy Mine [2], Coloma, Coloma Mining District, West Belt, El Dorado County, California, USAi
Regional Level Types | |
---|---|
McCurdy Mine [2] | Mine |
Coloma | - not defined - |
Coloma Mining District | Mining District |
West Belt | - not defined - |
El Dorado County | County |
California | State |
USA | Country |
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Latitude & Longitude (WGS84):
38° 49' 20'' North , 120° 53' 22'' West
Latitude & Longitude (decimal):
Type:
Köppen climate type:
Nearest Settlements:
Place | Population | Distance |
---|---|---|
Coloma | 529 (2011) | 2.5km |
Cold Springs | 446 (2011) | 9.1km |
Georgetown | 2,367 (2011) | 10.4km |
Auburn Lake Trails | 3,426 (2011) | 11.6km |
Placerville | 10,650 (2017) | 13.0km |
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 |
---|---|---|
El Dorado County Mineral and Gem Society | Placerville, California | 13km |
Gold Country Treasure Seekers | Placerville, California | 13km |
Roseville Rock Rollers | Roseville, California | 35km |
Fossils for Fun Society, Inc. | North Highlands, California | 45km |
Sacramento Valley Detecting Buffs | North Highlands, California | 45km |
Mindat Locality ID:
77910
Long-form identifier:
mindat:1:2:77910:3
GUID (UUID V4):
76440516-07de-496e-b770-ebad8893a03c
A former Cr-Fe occurrence/mine located in the NW¼ sec. 8, T11N, R10E, MDM, 2.5 km (1.5 miles) N of Coloma on the N side of Perry Mountain, E of Perry Mountain Creek and N of the South Fork American River (about 3 miles SW of Garden Valley), on private land. Owned by Rolland Armstrong, California (1976); and, G.O. Fisher, operator during WWI, California. MRDS database stated accuracy for this location is 500 meters.
The ore body strikes N30E and dips 00E at a width of 1.2 meters and a length of 4.2 meters. Ore body No. 1 is lenticular, disseminated. Ore body No. 2 is a shear zone. The primary mode of origin was magmatic differentiation. Primary ore control is lithology. Wallrock alteration is intense (carbonitization). Local rocks include Mesozoic volcanic rocks, unit 2 (Western Sierra Foothills and Western Klamath Mountains).
Workings include surface and underground openings comprised of open cuts and a 45 foot shaft.
According to Taliaferro, about 100 long tons of ore were shipped by 1918. The average minable grade of chromite is 33.5%. An additional 100 tons of ore was sorted and piled and was presumed shipped out. No accurate record of production exists. Operated by G.O. Fisher during WWI but no ore has been mined since although trails have been maintained to some of the workings and some exploration has been done. About 200 tons of ore containing 31 to 36% Cr2O3 produced during the period of active operation.
Reserves are small.
Select Mineral List Type
Standard Detailed Gallery Strunz Chemical ElementsDetailed Mineral List:
ⓘ Chromite Formula: Fe2+Cr3+2O4 |
ⓘ 'Serpentine Subgroup' Formula: D3[Si2O5](OH)4 |
ⓘ Talc Formula: Mg3Si4O10(OH)2 |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
Group 4 - Oxides and Hydroxides | |||
---|---|---|---|
ⓘ | Chromite | 4.BB.05 | Fe2+Cr3+2O4 |
Group 9 - Silicates | |||
ⓘ | Talc | 9.EC.05 | Mg3Si4O10(OH)2 |
Unclassified | |||
ⓘ | 'Serpentine Subgroup' | - | D3[Si2O5](OH)4 |
List of minerals for each chemical element
H | Hydrogen | |
---|---|---|
H | ⓘ Talc | Mg3Si4O10(OH)2 |
H | ⓘ Serpentine Subgroup | D3[Si2O5](OH)4 |
O | Oxygen | |
O | ⓘ Chromite | Fe2+Cr23+O4 |
O | ⓘ Talc | Mg3Si4O10(OH)2 |
O | ⓘ Serpentine Subgroup | D3[Si2O5](OH)4 |
Mg | Magnesium | |
Mg | ⓘ Talc | Mg3Si4O10(OH)2 |
Si | Silicon | |
Si | ⓘ Talc | Mg3Si4O10(OH)2 |
Si | ⓘ Serpentine Subgroup | D3[Si2O5](OH)4 |
Cr | Chromium | |
Cr | ⓘ Chromite | Fe2+Cr23+O4 |
Fe | Iron | |
Fe | ⓘ Chromite | Fe2+Cr23+O4 |
Other Databases
Link to USGS MRDS: | 10029961 |
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Other Regions, Features and Areas containing this locality
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References
(n.d.) Minerals Availability System (MAS), U.S. Bureau of Mines.file #0060170398