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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Orthoclase from
Etta Mine, Keystone, Keystone Mining District, Pennington County, South Dakota, USA


Locality type:Mine
Classification
Species:Orthoclase
Formula:K(AlSi3O8)
Comments:Occurs in a lithia pegmatite.
Confirmation
Validity:Believed Valid
Data
Mineral Data:Click here to view Orthoclase data
Locality Data:Click here to view Etta Mine, Keystone, Keystone Mining District, Pennington County, South Dakota, USA
Data Identifiers
Mindat Occurrence Record ID:64583
Long-form Identifier:1:3:64583:0
GUID (UUID V4):0
Nearest other occurrences of Orthoclase
1.2km (0.7 miles) ⓘHugo Mine, Keystone, Keystone Mining District, Pennington County, South Dakota, USA
9.2km (5.7 miles) ⓘBlack Elk Peak (Harney Peak), Pennington County, South Dakota, USA
54.0km (33.5 miles) ⓘGilt Edge Mine (Rattlesnake Jack; Dakota Maid; Ruby Ridge; Gilt Edge Glory Hole; Oro-Fina; Anchor Hill Mines 0460810072), Galena, Galena Mining District, Lawrence County, South Dakota, USA
54.7km (34.0 miles) ⓘBear Den Mountain, Galena, Galena Mining District, Lawrence County, South Dakota, USA
59.6km (37.0 miles) ⓘTerry, Lawrence County, South Dakota, USA
59.6km (37.1 miles) ⓘHomestake Mine, Lead, Lead Mining District, Lawrence County, South Dakota, USA
61.9km (38.4 miles) ⓘWharf Mine, Bald Mountain Mining District (Portland Mining District), Lawrence County, South Dakota, USA
65.7km (40.8 miles) ⓘTwin Peaks, Lead Mining District, Lawrence County, South Dakota, USA
70.4km (43.7 miles) ⓘSpearfish Peak (Black Butte), Spearfish, Lawrence County, South Dakota, USA
References
Dana 6: 1088
Rocks & Minerals: 10: 121-122,146-147.
USGS Bull 380D
 
and/or  
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