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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Sillimanite from
Thomaston Dam railroad cut, Thomaston Dam, Thomaston, Litchfield County, Connecticut, USA


Locality type:Road Cutting
Classification
Species:Sillimanite
Formula:Al2(SiO4)O
Formation:Primary
Comments:Accessory mineral in schist.
Habit:Fibrous
Quality for species:Rock forming mineral/non-crystalline/little interest for collectors.(##)
Confirmation
Validity:Believed Valid
Data
Mineral Data:Click here to view Sillimanite data
Locality Data:Click here to view Thomaston Dam railroad cut, Thomaston Dam, Thomaston, Litchfield County, Connecticut, USA
Data Identifiers
Mindat Occurrence Record ID:96383
Long-form Identifier:1:3:96383:3
GUID (UUID V4):0
Nearest other occurrences of Sillimanite
10.7km (6.7 miles) ⓘState Route 8 interchange 34 (formerly 37), Watertown, Litchfield County, Connecticut, USA
36.2km (22.5 miles) ⓘInterstate 84 road cuts (Route 6A bypass), Newtown, Fairfield County, Connecticut, USA
38.2km (23.8 miles) ⓘLittle Laurel Lime Park, Seymour, New Haven County, Connecticut, USA
38.4km (23.9 miles) ⓘCrissey Quarry (Crissy Hill), Norfolk, Litchfield County, Connecticut, USA
38.6km (24.0 miles) ⓘU. S. Route 7 Expressway (Danbury line to Iron Works District), Brookfield, Fairfield County, Connecticut, USA
39.8km (24.7 miles) ⓘRedwing Quarry, Falls Village, Canaan, Litchfield County, Connecticut, USA
41.2km (25.6 miles) ⓘDimension stone quarry, Collins Hill, Portland, Middlesex County, Connecticut, USA
45.1km (28.0 miles) ⓘGreat Hill cobalt mines, Cobalt, East Hampton, Middlesex County, Connecticut, USA
46.2km (28.7 miles) ⓘSunset Quartzite Quarry, East Glastonbury, Glastonbury, Hartford County, Connecticut, USA
46.9km (29.1 miles) ⓘOld Quarry Nature Center, Danbury, Fairfield County, Connecticut, USA
References
Januzzi, Ron E., Seaman, David M. (1976) Mineral Localities of Connecticut and Southeastern New York State and Pegmatite Minerals of the World. The Mineralogical Press, Danbury, Connecticut, USA.
 
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