Union Hill Quartz Mine (Union Hill Qtz; Gold Point; Centennial/Lucky/Cambridge; Union Hill vein; Cambridge-Lucky vein; Creek-Tungsten vein), Idaho-Maryland group, Grass Valley, Grass Valley Mining District, Nevada County, California, USAi
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Latitude & Longitude (WGS84):
39° 12' 45'' North , 121° 1' 18'' West
Latitude & Longitude (decimal):
Type:
Köppen climate type:
Nearest Settlements:
| Place | Population | Distance |
|---|---|---|
| Grass Valley | 12,944 (2017) | 3.5km |
| Nevada City | 3,152 (2017) | 5.5km |
| Alta Sierra | 6,911 (2011) | 8.4km |
| Rough and Ready | 963 (2011) | 10.0km |
| Colfax | 2,005 (2017) | 13.7km |
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 |
|---|---|---|
| Nevada County Gem & Mineral Society | Grass Valley, California | 3km |
| Sutter Buttes Gem & Mineral Society | Marysville, California | 50km |
A former lode Au-Zn-W-Pb occurrence/mine, located in sec. 25, & in the NE¼ sec. 36, T16N, R8E, MDM, about 3.6 km (2.2 miles) E of Grass Valley proper, NE of Union Hill, N of Cedar Ridge and SW of the county airport, on private (patented) land. The property comprises 23.11 acres. MRDS database stated accuracy for this location is 1,000 meters.
Mineralization is a vein deposit. The ore body is stringers and seams, strikes NW and dips SE. There are 3 veins carrying 2% sulfides. A scheelite stringer is 2 to 7 feet thick in the Creek-Tungsten vein. Schist is described as porphyritic and brecciated. Local rocks include Mesozoic volcanic rocks, unit 2 (Western Sierra Foothills and Western Klamath Mountains) and/or Tertiary pyroclastic and volcanic mudflow deposits, unit 9 (Cascade Range).
Workings include surface and underground openings with a length of 3,048 meters and an overall depth of 182.88 meters and comprised of shafts, a crosscut, drifts and stopes.
Production data are found in: MacBoyle, Errol (1919); Johnston, William Drumm (1940).
Ore from the Cambridge-Lucky vein averaged $20 (period values) per ton. The Union Hill vein was credited with production estimated at $500,000 to $750,000 (period values).
Select Mineral List Type
Standard Detailed Gallery Strunz Chemical ElementsMineral List
Mineral list contains entries from the region specified including sub-localities3 valid minerals.
Detailed Mineral List:
Gallery:
List of minerals arranged by Strunz 10th Edition classification
| Group 1 - Elements | |||
|---|---|---|---|
| ⓘ | Native Gold | 1.AA.05 | Au |
| Group 4 - Oxides and Hydroxides | |||
| ⓘ | Quartz | 4.DA.05 | SiO2 |
| Group 7 - Sulphates, Chromates, Molybdates and Tungstates | |||
| ⓘ | Scheelite | 7.GA.05 | Ca(WO4) |
List of minerals for each chemical element
| O | Oxygen | |
|---|---|---|
| O | ⓘ Quartz | SiO2 |
| O | ⓘ Scheelite | Ca(WO4) |
| Si | Silicon | |
| Si | ⓘ Quartz | SiO2 |
| Ca | Calcium | |
| Ca | ⓘ Scheelite | Ca(WO4) |
| W | Tungsten | |
| W | ⓘ Scheelite | Ca(WO4) |
| Au | Gold | |
| Au | ⓘ Native Gold | Au |
Other Databases
| Link to USGS MRDS: | 10031765 |
|---|
Localities in this Region
- California
- Nevada County
- Grass Valley Mining District
- Grass Valley
- Idaho-Maryland group
- Union Hill Quartz Mine (Union Hill Qtz; Gold Point; Centennial/Lucky/Cambridge; Union Hill vein; Cambridge-Lucky vein; Creek-Tungsten vein)
- Idaho-Maryland group
- Grass Valley
- Grass Valley Mining District
- Nevada County
Other Regions, Features and Areas containing this locality
North AmericaContinent
North America PlateTectonic Plate
- Foothills-Wallowa 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 #0060570353
