Keller Mine group (Dead Oak and Black Horse claims), Black Mountain, Black Wonder Mining District, Santa Clara County, California, USAi
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Latitude & Longitude (WGS84):
37° 22' 35'' North , 121° 27' 24'' West
Latitude & Longitude (decimal):
Köppen climate type:
Nearest Settlements:
| Place | Population | Distance |
|---|---|---|
| Diablo Grande | 826 (2017) | 15.8km |
| Westley | 603 (2011) | 29.8km |
| Patterson | 21,498 (2017) | 30.7km |
| East Foothills | 8,269 (2011) | 31.9km |
| Grayson | 952 (2011) | 32.1km |
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 |
|---|---|---|
| Santa Clara Valley Gem & Mineral Society | San Jose, California | 39km |
| Livermore Valley Lithophiles | Livermore, California | 44km |
| Mother Lode Mineral Society | Modesto, California | 50km |
A former Mn-silica occurrence/mine located in the N½N½NW¼ sec. 32, T6S, R5E, MDM, about 6.0 km NNW of Black Mountain (summit), along the W canyon wall of Beauregard Creek, on private land (fee ownership). Discovered in 1940. Owned by G.L. & K.L. Colonica (100%), San Jose, California (1975). First produced in 1941. MRDS database stated accuracy for this location is 100 meters. The claims are ½ mile apart along the N border of sec. 32.
Mineralization is hosted in Late Cretaceous chert. The ore body strikes N30W and dips 85S at a thickness of 7 meters, depth-to-top of 1 meter, width of 3 meters and a length of 35 meters. Ore body No. 1 is sedimentary and lenticular. Ore body No. 2 is a shear zone. The primary mode of origin was sedimentation and the secondary mode was oxidation. Primary ore control was lithology and the secondary control was bedding. The ore is hosted in Franciscan complex rocks. The ore body pinched out at a depth of 35 feet and was separated from wallrock, that consisted of leached, thin-bedded chert. A fine clay zone occurs along walls suggests that the ore body is limited by faults. The chert zone in which the ore is found can be traced for 100 yards S, where it abuts a large mass of glaucophane schist. The ore consists of black Mn oxide. Wallrock alteration is slight (intermediate argillic). Local rocks include rocks of the Franciscan melange.
Workings include unspecified surface openings.
Analytical data results: The average grade of the ore is 45% Mn.
Select Mineral List Type
Standard Detailed Gallery Strunz Chemical ElementsCommodity List
This is a list of exploitable or exploited mineral commodities recorded at this locality.Mineral List
1 valid mineral.
Rock Types Recorded
Note: data is currently VERY limited. Please bear with us while we work towards adding this information!
Select Rock List Type
Alphabetical List Tree DiagramDetailed Mineral List:
| ⓘ Glaucophane Formula: ◻[Na2][Mg3Al2]Si8O22(OH)2 |
| ⓘ 'Psilomelane' |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
| Group 9 - Silicates | |||
|---|---|---|---|
| ⓘ | Glaucophane | 9.DE.25 | ◻[Na2][Mg3Al2]Si8O22(OH)2 |
| Unclassified | |||
| ⓘ | 'Psilomelane' | - | |
List of minerals for each chemical element
| H | Hydrogen | |
|---|---|---|
| H | ⓘ Glaucophane | ◻[Na2][Mg3Al2]Si8O22(OH)2 |
| O | Oxygen | |
| O | ⓘ Glaucophane | ◻[Na2][Mg3Al2]Si8O22(OH)2 |
| Na | Sodium | |
| Na | ⓘ Glaucophane | ◻[Na2][Mg3Al2]Si8O22(OH)2 |
| Mg | Magnesium | |
| Mg | ⓘ Glaucophane | ◻[Na2][Mg3Al2]Si8O22(OH)2 |
| Al | Aluminium | |
| Al | ⓘ Glaucophane | ◻[Na2][Mg3Al2]Si8O22(OH)2 |
| Si | Silicon | |
| Si | ⓘ Glaucophane | ◻[Na2][Mg3Al2]Si8O22(OH)2 |
Other Databases
| Link to USGS MRDS: | 10077449 |
|---|
Other Regions, Features and Areas containing this locality
North AmericaContinent
- Coast MountainsMountain Range
North America PlateTectonic Plate
- California Coast RangesAccretionary Complex
- Franciscan DomainDomain
USA
- California
- Diablo RangeMountain Range
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