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
Portland Harbour Trust Quarry, Cape Sir William Grant, Portland, Glenelg Shire, Victoria, Australia


Locality type:Quarry
Classification
Species:Montmorillonite
Formula:(Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2 · nH2O
Comments:"A clay mineral, probably montmorillonite, which ranges in colour from dark greenish black to pale grey or brown, forms a thin coating over many andesine, augite and ilmanite crystals."
Confirmation
Validity:Believed Valid
Data
Mineral Data:Click here to view Montmorillonite data
Locality Data:Click here to view Portland Harbour Trust Quarry, Cape Sir William Grant, Portland, Glenelg Shire, Victoria, Australia
Data Identifiers
Mindat Occurrence Record ID:92085
Long-form Identifier:1:3:92085:6
GUID (UUID V4):0
References
Birch, W. D. - Ed. (1989) Zeolites of Victoria. Special Publication No.2. Mineralogical Society of Victoriapp.86-89
 
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