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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Heulandite Subgroup from
Tilly Foster Iron Mine, Town of Southeast, Putnam County, New York, USA


Locality type:Mine
Classification
Species:'Heulandite Subgroup' (not an IMA approved species)
Formula:(Na/Ca/K)5-6[Al8-9 Si27-28 O72] · nH2O
Comments:Small cleavages and crystals occur in cavities and seams in gneiss
Confirmation
Validity:Believed Valid
Data
Mineral Data:Click here to view Heulandite Subgroup data
Locality Data:Click here to view Tilly Foster Iron Mine, Town of Southeast, Putnam County, New York, USA
Data Identifiers
Mindat Occurrence Record ID:100218
Long-form Identifier:1:3:100218:8
GUID (UUID V4):0
Nearest other occurrences of Heulandite Subgroup
1.9km (1.2 miles) ⓘInterstate 84 road cuts, Town of Southeast, Putnam County, New York, USA
15.5km (9.6 miles) ⓘNorth Street mall, Danbury, Fairfield County, Connecticut, USA
23.4km (14.5 miles) ⓘFillow Quarry, Branchville, Redding, Fairfield County, Connecticut, USA
25.0km (15.5 miles) ⓘState Route 57 zeolite occurrence (Georgetown locality; Connerie's store), Redding, Fairfield County, Connecticut, USA
33.3km (20.7 miles) ⓘNew York City Aquaduct openings, Ossining (Sing Sing), Westchester County, New York, USA
33.6km (20.8 miles) ⓘNew England Materials quarry, Monroe, Fairfield County, Connecticut, USA
36.9km (22.9 miles) ⓘOld Mine Plaza construction site, Long Hill, Trumbull, Fairfield County, Connecticut, USA
37.2km (23.1 miles) ⓘO & G Southbury Quarry (Silliman Quarry; O & G No. 2 Quarry), Orenaug Hills, Woodbury, Litchfield County, Connecticut, USA
41.0km (25.5 miles) ⓘNonnewaug River Industrial Park, Woodbury, Litchfield County, Connecticut, USA
43.8km (27.2 miles) ⓘInterstate 95 exit 24, Fairfield, Fairfield County, Connecticut, USA
References
(Januzzi, 1966, 1989) (Trainer, 1939).
Jensen (1978) Minerals of New York State, 42-43
 
and/or  
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