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


Locality type:Mine
Classification
Species:Opal
Formula:SiO2 · nH2O
Comments:Occurs as small grayish white coating on various minerals
Habit:coatings
Colour:grayish-white
Quality for species:Poor for species, only of interest for locality collectors. (#)
Confirmation
Validity:Believed Valid
Data
Mineral Data:Click here to view Opal 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:100228
Long-form Identifier:1:3:100228:7
GUID (UUID V4):0
Nearest other occurrences of Opal
1.9km (1.2 miles) ⓘInterstate 84 road cuts, Town of Southeast, Putnam County, New York, USA
12.5km (7.7 miles) ⓘWestern Connecticut State University, Danbury, Fairfield County, Connecticut, USA
15.5km (9.6 miles) ⓘNorth Street mall, Danbury, Fairfield County, Connecticut, USA
16.8km (10.4 miles) ⓘCasey Quarry (Ridgefield pegmatite), Ridgefield, Fairfield County, Connecticut, USA
20.9km (13.0 miles) ⓘCroft Mine (Croft Magnetic Iron Mine), Peekskill, Westchester County, New York, USA
21.0km (13.1 miles) ⓘU. S. Route 7 Expressway (Danbury line to Iron Works District), Brookfield, Fairfield County, Connecticut, USA
21.2km (13.2 miles) ⓘPhillips ore bed, Town of Putnam Valley, Putnam County, New York, USA
23.2km (14.4 miles) ⓘBedford, Westchester County, New York, USA
23.4km (14.5 miles) ⓘFillow Quarry, Branchville, Redding, Fairfield County, Connecticut, USA
23.6km (14.6 miles) ⓘSky Ridge railroad cut, Hawleyville, Newtown, Fairfield County, Connecticut, USA
References
(Januzzi, 1966, 1989) (Trainer, 1938).
Jensen (1978) Minerals of New York State, 42-43
 
and/or  
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