Alstead-North Hillcrest mine, Cuyuna North Range, Crow Wing County, Minnesota, USAi
| Regional Level Types | |
|---|---|
| Alstead-North Hillcrest mine | Mine (Flooded) |
| Cuyuna North Range | Mountain Range |
| Crow Wing County | County |
| Minnesota | State |
| USA | Country |
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Latitude & Longitude (WGS84):
46° 28' 59'' North , 94° 0' 21'' West
Latitude & Longitude (decimal):
Type:
Mine (Flooded) - last checked 2023
Köppen climate type:
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 |
|---|---|---|
| Cuyuna Rock, Gem and Mineral Society | Brainerd, Minnesota | 20km |
The Alstead and North Hillcrest open-pit mines are now considered a unit and part of a group that includes the Arko and Hillcrest Extension pits, herein described separately. The North Hillcrest mine was opened in 1928 and the Alstead in 1929. The Alstead, North Hillcrest, Hillcrest Extension, and Arko mines together produced 3,270,489 tons of ore through 1955. The group of mines is operated by the Hanna Coal and Ore Corp.
The ore consisted of two separated bodies,complexly folded and faulted. Both were part of the Proterozoic Trommald Formation. Both thick and thin bedded cherty banded iron formation were present. The ore was manganiferous. Unaltered ore was rich in siderite, quartz, stilpnomelane and minnesotaite were common, as were thick veins with these minerals. The underlying Mahnomen Formation was also well exposed in the pit and consisted of quartzite, argillite and slate. The flooded pit and overgrown dumps of the mine site are now a major part of the Cuyuna Country State Recreation area. It is administered by the Minnesota Department of Natural Resources, and no collecting is permitted.
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Standard Detailed Gallery Strunz Chemical ElementsCommodity List
This is a list of exploitable or exploited mineral commodities recorded at this locality.Mineral List
7 valid minerals.
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:
| ⓘ Baryte Formula: BaSO4 References: |
| ⓘ Hematite Formula: Fe2O3 |
| ⓘ Magnetite Formula: Fe2+Fe3+2O4 |
| ⓘ Minnesotaite Formula: Fe2+3Si4O10(OH)2 References: |
| ⓘ Quartz Formula: SiO2 References: |
| ⓘ Siderite Formula: FeCO3 References: |
| ⓘ Stilpnomelane Formula: (K,Ca,Na)(Fe,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O References: |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
| Group 4 - Oxides and Hydroxides | |||
|---|---|---|---|
| ⓘ | Magnetite | 4.BB.05 | Fe2+Fe3+2O4 |
| ⓘ | Hematite | 4.CB.05 | Fe2O3 |
| ⓘ | Quartz | 4.DA.05 | SiO2 |
| Group 5 - Nitrates and Carbonates | |||
| ⓘ | Siderite | 5.AB.05 | FeCO3 |
| Group 7 - Sulphates, Chromates, Molybdates and Tungstates | |||
| ⓘ | Baryte | 7.AD.35 | BaSO4 |
| Group 9 - Silicates | |||
| ⓘ | Minnesotaite | 9.EC.05 | Fe2+3Si4O10(OH)2 |
| ⓘ | Stilpnomelane | 9.EG.40 | (K,Ca,Na)(Fe,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O |
List of minerals for each chemical element
| H | Hydrogen | |
|---|---|---|
| H | ⓘ Minnesotaite | Fe32+Si4O10(OH)2 |
| H | ⓘ Stilpnomelane | (K,Ca,Na)(Fe,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O |
| C | Carbon | |
| C | ⓘ Siderite | FeCO3 |
| O | Oxygen | |
| O | ⓘ Baryte | BaSO4 |
| O | ⓘ Hematite | Fe2O3 |
| O | ⓘ Magnetite | Fe2+Fe23+O4 |
| O | ⓘ Minnesotaite | Fe32+Si4O10(OH)2 |
| O | ⓘ Quartz | SiO2 |
| O | ⓘ Siderite | FeCO3 |
| O | ⓘ Stilpnomelane | (K,Ca,Na)(Fe,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O |
| Na | Sodium | |
| Na | ⓘ Stilpnomelane | (K,Ca,Na)(Fe,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O |
| Mg | Magnesium | |
| Mg | ⓘ Stilpnomelane | (K,Ca,Na)(Fe,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O |
| Al | Aluminium | |
| Al | ⓘ Stilpnomelane | (K,Ca,Na)(Fe,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O |
| Si | Silicon | |
| Si | ⓘ Minnesotaite | Fe32+Si4O10(OH)2 |
| Si | ⓘ Quartz | SiO2 |
| Si | ⓘ Stilpnomelane | (K,Ca,Na)(Fe,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O |
| S | Sulfur | |
| S | ⓘ Baryte | BaSO4 |
| K | Potassium | |
| K | ⓘ Stilpnomelane | (K,Ca,Na)(Fe,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O |
| Ca | Calcium | |
| Ca | ⓘ Stilpnomelane | (K,Ca,Na)(Fe,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O |
| Fe | Iron | |
| Fe | ⓘ Hematite | Fe2O3 |
| Fe | ⓘ Magnetite | Fe2+Fe23+O4 |
| Fe | ⓘ Minnesotaite | Fe32+Si4O10(OH)2 |
| Fe | ⓘ Siderite | FeCO3 |
| Fe | ⓘ Stilpnomelane | (K,Ca,Na)(Fe,Mg,Al)8(Si,Al)12(O,OH)36 · nH2O |
| Ba | Barium | |
| Ba | ⓘ Baryte | BaSO4 |
Other Databases
| Link to USGS MRDS: | 10195284 |
|---|
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Alstead-North Hillcrest mine, Cuyuna North Range, Crow Wing County, Minnesota, USA