Vote for your favorite mineral in #MinCup26! - Quartz vs. Asagiite
It's a classic vs a newbie as the most common named mineral in the crust Quartz is up against an exceedingly-rare sea foam-green mineral discovered just a few years ago Asagiite.
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Thompson mine, Portsmouth Mine, Cuyuna North Range, Crow Wing County, Minnesota, USAi
Regional Level Types
Thompson mineMine (Swallowed up by other workings)
Portsmouth MineMine (Flooded)
Cuyuna North RangeMountain Range
Crow Wing CountyCounty
MinnesotaState
USACountry

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Latitude & Longitude (WGS84):
46° 29' 10'' North , 93° 57' 46'' West
Latitude & Longitude (decimal):
46.48618,-93.96304
GeoHash:
G#: cbm0myd1w
GRN:
N31W48
Type:
Mine (Swallowed up by other workings) - last checked 2023
Deposit first discovered:
1911
Köppen climate type:
Dfb : Warm-summer humid continental climate
Nearest Settlements:
PlacePopulationDistance
Crosby2,345 (2017)0.6km
Ironton561 (2017)1.5km
Cuyuna346 (2017)4.6km
Trommald101 (2017)4.7km
Deerwood520 (2017)5.1km
Nearest Clubs:
Local clubs are the best way to get access to collecting localities
ClubLocationDistance
Cuyuna Rock, Gem and Mineral SocietyBrainerd, Minnesota23km
Mindat Locality ID:
52897
Long-form identifier:
mindat:1:2:52897:0
GUID (UUID V4):
0


The Thompson Mine (Sec 11 T46N R29W) was opened by Inland Steel in 1911. It consisted both of underground and open pit operations. It worked ore from the ferruginous chert and argillite of the Proterozoic Trommald Formation. It was eventually absorbed by the large open pit Portsmouth Mine.

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Commodity List

This is a list of exploitable or exploited mineral commodities recorded at this locality.


Mineral List


1 valid mineral.

Detailed Mineral List:

ⓘ 'Chlorite Group'
ⓘ Hematite
Formula: Fe2O3

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Group 4 - Oxides and Hydroxides
ⓘHematite4.CB.05Fe2O3
Unclassified
ⓘ'Chlorite Group'-

List of minerals for each chemical element

OOxygen
Oⓘ HematiteFe2O3
FeIron
Feⓘ HematiteFe2O3

Other Regions, Features and Areas containing this locality

North AmericaContinent
North America PlateTectonic Plate

This page contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to visit any sites listed in mindat.org without first ensuring that you have the permission of the land and/or mineral rights holders for access and that you are aware of all safety precautions necessary.

References

Schmidt, R.G. (1963) Geology and ore deposits of the Cuyuna North Range, Minnesota: U.S. Geological Survey Professional Paper 407, 96 p.
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