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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Phillipsite Subgroup from
Thomaston Dam railroad cut, Thomaston Dam, Thomaston, Litchfield County, Connecticut, USA


09100960017272018139955.jpg
Harmotome, etc.

Thomaston Dam railroad cut, Thomaston Dam, Thomaston, Litchfield County, Connecticut, USA
06125920017272018806318.jpg
Harmotome

Thomaston Dam railroad cut, Thomaston Dam, Thomaston, Litchfield County, Connecticut, USA
00978080017272018211119.jpg
Harmotome, etc.

Thomaston Dam railroad cut, Thomaston Dam, Thomaston, Litchfield County, Connecticut, USA
01923260017272018857179.jpg
Harmotome, etc.

Thomaston Dam railroad cut, Thomaston Dam, Thomaston, Litchfield County, Connecticut, USA
05600740017366988088903.jpg
Harmotome, etc.

Thomaston Dam railroad cut, Thomaston Dam, Thomaston, Litchfield County, Connecticut, USA
06125920017272018806318.jpg
Harmotome

Thomaston Dam railroad cut, Thomaston Dam, Thomaston, Litchfield County, Connecticut, USA
09506950017367309887251.jpg
Harmotome, etc.

Thomaston Dam railroad cut, Thomaston Dam, Thomaston, Litchfield County, Connecticut, USA
01923260017272018857179.jpg
Harmotome, etc.

Thomaston Dam railroad cut, Thomaston Dam, Thomaston, Litchfield County, Connecticut, USA
09100960017272018139955.jpg
Harmotome, etc.

Thomaston Dam railroad cut, Thomaston Dam, Thomaston, Litchfield County, Connecticut, USA
06125920017272018806318.jpg
Harmotome

Thomaston Dam railroad cut, Thomaston Dam, Thomaston, Litchfield County, Connecticut, USA
00978080017272018211119.jpg
Harmotome, etc.

Thomaston Dam railroad cut, Thomaston Dam, Thomaston, Litchfield County, Connecticut, USA
01923260017272018857179.jpg
Harmotome, etc.

Thomaston Dam railroad cut, Thomaston Dam, Thomaston, Litchfield County, Connecticut, USA
Locality type:Road Cutting
Classification
Species:'Phillipsite Subgroup' (not an IMA approved species)
Formula:(Ca0.5,K,Na,Ba0.5)4-7[Al4-7Si12-9O32] . 12H2O
Comments:This zeolite has the same morphology as harmotome, but according to Tschernich's 1992 "Zeolites of the World", harmotome is typical of lead deposits whereas phillipsite occurs in volcanics. This locality is thus favorable for harmotome. Henderson (1979) analyzed crystals and found that "...microprobe analysis shows the Ba:Si ratio to be 1.2:6, and the amounts of K, Na and Ca to be low. This data fits harmotome perfectly, and is not consistent with either phillipsite or wellsite."
Confirmation
Validity:Erroneously Reported
Data
Mineral Data:Click here to view Phillipsite Subgroup data
Locality Data:Click here to view Thomaston Dam railroad cut, Thomaston Dam, Thomaston, Litchfield County, Connecticut, USA
Data Identifiers
Mindat Occurrence Record ID:657240
Long-form Identifier:1:3:657240:2
GUID (UUID V4):0
References
Henderson, William A. (1979) Microminerals (Column) The Mineralogical Record, 10 (4) 239-241
 
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