Vote for your favorite mineral in #MinCup26! - Sphalerite vs. Anorthite
Both zinc ore Sphalerite and calcium plagioclase feldspar Anorthite have perfect cleavage that will split cleanly if you hit them with a hammer, but only one can claim a larger split of your votes!
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Horseshoe Mountain, Snoqualmie Mining District, King County, Washington, USAi
Regional Level Types
Horseshoe MountainMountain
Snoqualmie Mining DistrictMining District
King CountyCounty (Historical)
WashingtonState
USACountry

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Latitude & Longitude (WGS84):
47° 27' 30'' North , 121° 38' 6'' West
Latitude & Longitude (decimal):
47.45860,-121.63520
GeoHash:
G#: c23tbpefq
GRN:
N32W60
Type:
Mountain
Köppen climate type:
Csb : Warm-summer Mediterranean climate
Nearest Settlements:
PlacePopulationDistance
Tanner1,018 (2011)8.5km
Riverbend2,132 (2011)8.7km
Wilderness Rim1,523 (2017)10.1km
North Bend6,679 (2017)12.1km
Snoqualmie13,169 (2017)16.3km
Nearest Clubs:
Local clubs are the best way to get access to collecting localities
ClubLocationDistance
Bellevue Rock Club, Inc.Bellevue, Washington46km
Cascade Mineralogical Society IncKent, Washington46km
North American Miners AssociationKent, Washington46km
East KingCo Rock ClubKirkland, Washington50km
Mindat Locality ID:
15526
Long-form identifier:
mindat:1:2:15526:0
GUID (UUID V4):
0


On Horseshoe Mountain arfvedsonite occurs as bladed crystals in pockets in anorthosite.

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Mineral List


1 valid mineral.

Detailed Mineral List:

ⓘ Arfvedsonite
Formula: [Na][Na2][Fe2+4Fe3+]Si8O22(OH)2
Habit: blocky to bladed crystals to 1.5"
Description: crystals in mairolitic cavities and as a rockforming mineral

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Group 9 - Silicates
ⓘArfvedsonite9.DE.25[Na][Na2][Fe2+4Fe3+]Si8O22(OH)2

List of minerals for each chemical element

HHydrogen
Hⓘ Arfvedsonite[Na][Na2][Fe42+Fe3+]Si8O22(OH)2
OOxygen
Oⓘ Arfvedsonite[Na][Na2][Fe42+Fe3+]Si8O22(OH)2
NaSodium
Naⓘ Arfvedsonite[Na][Na2][Fe42+Fe3+]Si8O22(OH)2
SiSilicon
Siⓘ Arfvedsonite[Na][Na2][Fe42+Fe3+]Si8O22(OH)2
FeIron
Feⓘ Arfvedsonite[Na][Na2][Fe42+Fe3+]Si8O22(OH)2

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

Cannon, Bart (1975) Minerals of Washington. Cordilleran, Mercer Island, WA.p.49
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