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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Montmorillonite from
Unnamed abandoned quarry (Unnamed small gravel quarry), Claremont, Los Angeles County, California, USA


Locality type:Quarry
Classification
Species:Montmorillonite
Formula:(Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2 · nH2O
Comments:Occurs in pegmatite as an apparent alteration product of feldspar. Waxy.
Confirmation
Validity:Believed Valid
Associated Minerals:
Associates:Albite
Orthoclase
Quartz
Data
Mineral Data:Click here to view Montmorillonite data
Locality Data:Click here to view Unnamed abandoned quarry (Unnamed small gravel quarry), Claremont, Los Angeles County, California, USA
Data Identifiers
Mindat Occurrence Record ID:683408
Long-form Identifier:1:3:683408:1
GUID (UUID V4):0
Nearest other occurrences of Montmorillonite
33.2km (20.6 miles) ⓘCommercial Quarry, Sky Blue Hill, Crestmore quarries, Crestmore, Jurupa Valley, Riverside County, California, USA
67.9km (42.2 miles) ⓘRobertson Clay Mine, Apple Valley, San Bernardino County, California, USA
87.1km (54.1 miles) ⓘOverman property, Castaic Junction, Los Angeles County, California, USA
95.8km (59.5 miles) ⓘAnita Mine (Magee Mine; Magee & Dougherty Mine; Sage Mine), Red Mountain, Cahuilla Mining District, Riverside County, California, USA
References
Laudermilk, J. D., Woodford, A. O. (1934) Secondary montmorillonite in a California pegmatite. American Mineralogist, 19 (6) 260-267
Sharp, W.E. (1959) Minerals from Los Angeles County, California. Printed privately, Los Angeles, California: 42, 90
Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 273
Pemberton, H. Earl (1983) Minerals of California. Van Nostrand Reinhold Company Inc.
 
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