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Good Harbor Bay, Grand Marais, Cook County, Minnesota, USAi
Regional Level Types
Good Harbor BayBeach
Grand MaraisCity
Cook CountyCounty
MinnesotaState
USACountry

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PhotosMapsSearch
08190410017575152419922.jpg
Thomsonite-Ca

Good Harbor Bay, Grand Marais, Cook County, Minnesota, USA
03116350017272040031137.jpg
Thomsonite-Ca

Good Harbor Bay, Grand Marais, Cook County, Minnesota, USA
02499060017272040052749.jpg
Thomsonite-Ca

Good Harbor Bay, Grand Marais, Cook County, Minnesota, USA
03915700017362669125710.jpg
Thomsonite-Ca

Good Harbor Bay, Grand Marais, Cook County, Minnesota, USA
03116350017272040031137.jpg
Thomsonite-Ca

Good Harbor Bay, Grand Marais, Cook County, Minnesota, USA
02499060017272040052749.jpg
Thomsonite-Ca

Good Harbor Bay, Grand Marais, Cook County, Minnesota, USA
08190410017575152419922.jpg
Thomsonite-Ca

Good Harbor Bay, Grand Marais, Cook County, Minnesota, USA
03116350017272040031137.jpg
Thomsonite-Ca

Good Harbor Bay, Grand Marais, Cook County, Minnesota, USA
Latitude & Longitude (WGS84):
47° 43' 46'' North , 90° 26' 25'' West
Latitude & Longitude (decimal):
47.72972,-90.44028
GRN:
N32W45
Type:
Beach - last checked 2026
Köppen climate type:
Dfb : Warm-summer humid continental climate
Nearest Settlements:
PlacePopulationDistance
Grand Marais1,327 (2017)8.3km
Lutsen190 (2017)19.8km
Mindat Locality ID:
16150
Long-form identifier:
mindat:1:2:16150:8
GUID (UUID V4):
0
Other/historical names associated with this locality:
Thomsonite Beach


Famous occurrence for nodules of zeolites usually labeled thomsonite, though other zeolites, such as mesolite, are present as well. A green massive form of thomsonite named lintonite is also found here.

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Mineral List


6 valid minerals.

Detailed Mineral List:

ⓘ Calcite
Formula: CaCO3
References:
Samuel Anderson CollectionIdentified by Samuel Anderson: Visual Identification
ⓘ Laumontite
Formula: CaAl2Si4O12 · 4H2O
References:
Samuel Anderson CollectionIdentified by Samuel Anderson: Visual Identification
ⓘ Pumpellyite-(Fe2+) ?
Formula: Ca2Fe2+Al2[Si2O6OH][SiO4](OH)2(OH)
References:
Samuel Anderson CollectionIdentified by Samuel Anderson: Visual Identification
ⓘ Quartz
Formula: SiO2
References:
Samuel Anderson CollectionIdentified by Samuel Anderson: Visual Identification
ⓘ Saponite
Formula: Ca0.25(Mg,Fe)3((Si,Al)4O10)(OH)2 · nH2O
References:
Samuel Anderson CollectionIdentified by Samuel Anderson: Visual Identification
ⓘ Thomsonite-Ca
Formula: NaCa2[Al5Si5O20] · 6H2O

List of minerals arranged by Strunz 10th Edition classification

Group 4 - Oxides and Hydroxides
ⓘQuartz4.DA.05SiO2
Group 5 - Nitrates and Carbonates
ⓘCalcite5.AB.05CaCO3
Group 9 - Silicates
ⓘPumpellyite-(Fe2+) ?9.BG.20Ca2Fe2+Al2[Si2O6OH][SiO4](OH)2(OH)
ⓘSaponite9.EC.45Ca0.25(Mg,Fe)3((Si,Al)4O10)(OH)2 · nH2O
ⓘThomsonite-Ca9.GA.10NaCa2[Al5Si5O20] · 6H2O
ⓘLaumontite9.GB.10CaAl2Si4O12 · 4H2O

List of minerals for each chemical element

HHydrogen
Hⓘ LaumontiteCaAl2Si4O12 · 4H2O
Hⓘ Pumpellyite-(Fe2+)Ca2Fe2+Al2[Si2O6OH][SiO4](OH)2(OH)
Hⓘ SaponiteCa0.25(Mg,Fe)3((Si,Al)4O10)(OH)2 · nH2O
Hⓘ Thomsonite-CaNaCa2[Al5Si5O20] · 6H2O
CCarbon
Cⓘ CalciteCaCO3
OOxygen
Oⓘ CalciteCaCO3
Oⓘ LaumontiteCaAl2Si4O12 · 4H2O
Oⓘ Pumpellyite-(Fe2+)Ca2Fe2+Al2[Si2O6OH][SiO4](OH)2(OH)
Oⓘ QuartzSiO2
Oⓘ SaponiteCa0.25(Mg,Fe)3((Si,Al)4O10)(OH)2 · nH2O
Oⓘ Thomsonite-CaNaCa2[Al5Si5O20] · 6H2O
NaSodium
Naⓘ Thomsonite-CaNaCa2[Al5Si5O20] · 6H2O
MgMagnesium
Mgⓘ SaponiteCa0.25(Mg,Fe)3((Si,Al)4O10)(OH)2 · nH2O
AlAluminium
Alⓘ LaumontiteCaAl2Si4O12 · 4H2O
Alⓘ Pumpellyite-(Fe2+)Ca2Fe2+Al2[Si2O6OH][SiO4](OH)2(OH)
Alⓘ SaponiteCa0.25(Mg,Fe)3((Si,Al)4O10)(OH)2 · nH2O
Alⓘ Thomsonite-CaNaCa2[Al5Si5O20] · 6H2O
SiSilicon
Siⓘ LaumontiteCaAl2Si4O12 · 4H2O
Siⓘ Pumpellyite-(Fe2+)Ca2Fe2+Al2[Si2O6OH][SiO4](OH)2(OH)
Siⓘ QuartzSiO2
Siⓘ SaponiteCa0.25(Mg,Fe)3((Si,Al)4O10)(OH)2 · nH2O
Siⓘ Thomsonite-CaNaCa2[Al5Si5O20] · 6H2O
CaCalcium
Caⓘ CalciteCaCO3
Caⓘ LaumontiteCaAl2Si4O12 · 4H2O
Caⓘ Pumpellyite-(Fe2+)Ca2Fe2+Al2[Si2O6OH][SiO4](OH)2(OH)
Caⓘ SaponiteCa0.25(Mg,Fe)3((Si,Al)4O10)(OH)2 · nH2O
Caⓘ Thomsonite-CaNaCa2[Al5Si5O20] · 6H2O
FeIron
Feⓘ Pumpellyite-(Fe2+)Ca2Fe2+Al2[Si2O6OH][SiO4](OH)2(OH)
Feⓘ SaponiteCa0.25(Mg,Fe)3((Si,Al)4O10)(OH)2 · nH2O

Other Regions, Features and Areas containing this locality

North AmericaContinent
North America PlateTectonic Plate
USA

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

Winchell, N. H. (1898), Thomsonite and lintonite from the north shore of Lake Superior - American Geologist: 22(6): 347-349.
Hanley, F. B. (1919), New accessibility of Thomsonite Beach, Minnesota - American Mineralogist: 24: 726-727.
Dahlberg, J. C. (1962), Laura A. Linton and Lintonite – Minnesota History: 38: 21-23.
Leatherman, Mark (2017) Radiant Minnesota Thomsonite: the world's most colorful opaque gemstone - Rock and Gem: 47(9): 58-61.
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