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
Andrews Quarry (old Hale Quarry; Grandfather Andrews Quarry), Portland, Middlesex County, Connecticut, USA


Locality type:Quarry
Classification
Species:Montmorillonite
Formula:(Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2 · nH2O
Comments:Zodac (1941) was referring to the Hale Quarry as the Andrews Quarry so this report is erroneous.
Confirmation
Validity:Erroneously Reported
Data
Mineral Data:Click here to view Montmorillonite data
Locality Data:Click here to view Andrews Quarry (old Hale Quarry; Grandfather Andrews Quarry), Portland, Middlesex County, Connecticut, USA
Data Identifiers
Mindat Occurrence Record ID:147362
Long-form Identifier:1:3:147362:9
GUID (UUID V4):0
Nearest other occurrences of Montmorillonite
0.3km (0.2 miles) ⓘHale Quarry (Andrews Quarry; Glastonbury Quarry), Portland, Middlesex County, Connecticut, USA
1.4km (0.9 miles) ⓘWalden Gem Quarry, Portland, Middlesex County, Connecticut, USA
4.4km (2.7 miles) ⓘStrickland Quarry, Strickland pegmatite, Collins Hill, Portland, Middlesex County, Connecticut, USA
17.1km (10.6 miles) ⓘGillette Quarry (J-J Mine; Haddam Neck Quarry), Haddam Neck, Haddam, Middlesex County, Connecticut, USA
39.6km (24.6 miles) ⓘThomaston Dam railroad cut, Thomaston Dam, Thomaston, Litchfield County, Connecticut, USA
67.2km (41.8 miles) ⓘBlandford mica mines, Blandford, Hampden County, Massachusetts, USA
70.7km (43.9 miles) ⓘKent Iron Mine (Limonite mine), Kent, Litchfield County, Connecticut, USA
71.9km (44.7 miles) ⓘDiamond Hill (Ashaway Village), Ashaway, Hopkinton, Washington County, Rhode Island, USA
73.1km (45.4 miles) ⓘLoudville Lead Mines (Manhan Lead-Silver Mine; Southampton Lead Mine; Northampton Lead Mine), Easthampton, Hampshire County, Massachusetts, USA
80.8km (50.2 miles) ⓘFillow Quarry, Branchville, Redding, Fairfield County, Connecticut, USA
References
Rocks & Min.: 16: 164-167.
 
and/or  
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