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Photos recently added to NH species galleries, set #114. | |
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Species: SCHORL Locality: Charles Davis Mine, N. Groton, NH Specimen Size: Complete 1.5 cm tourmaline crystal in pegmatite matrix. Field Collected: Tom Mortimer - 8/19 Catalog No.: 2112 Notes: This tourmaline is very brown, suggesting a visual identification of dravite. A 10/19 polished grain EDS analysis (BC361) showed Fe about twice Mg, so schorl Mindat.org provides a general tourmaline group formula of: A(D3)G6(Si6O18)(BO3)3X3Z A = Ca, Na, K, or is vacant (large cations); D = Al, Fe2+, Fe3+, Li, Mg2+, Mn2+ (intermediate to small cations - in valence balancing combinations when the A site is vacant); G = Al, Cr3+, Fe3+, V3+ (small cations); Si can sometimes have minor Al and/or B3+ substitution. X = O and/or OH; Z = F, O and/or OH. The elements in the BC261 analysis are all ones allowed in a tourmaline composition. The EDS detector will not sense Li or B. This Charles Davis tourmaline is iron dominant. |
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Species: ARSENOPYRITE Locality: Dodge Gold Mine, Lyman, NH Specimen Size: 2.5 mm crystal group, two views Field Collected: Cliff Trebilcock Catalog No.: u2280 Notes: |
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Species: HYDROZINCITE Locality: Mascot Mine, Gorham, NH Specimen Size: 10 mm field of view, first photo Field Collected: Cliff Trebilcock Catalog No.: A Cliff Trebilcock specimen Notes: White hydrozincite coating a prismatic mineral. My first guess for this substrate mineral was hemimorphite. Cerussite seemed possible also. Cliff emailed me after my posting that Al Falster of the Maine Mineral Museum lab had determined the underlying mineral to be calcite or aragonite. The hydrozincite is fluorescent bright white. |
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Species: CHALCOPYRITE Locality: Mascot Mine, Gorham, NH Specimen Size: 3.5 mm chalcopyrite crystal with quartz crystals Field Collected: Cliff Trebilcock Catalog No.: A Cliff Trebilcock specimen Notes: |
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Species: CHALCOPYRITE Locality: Mascot Mine, Gorham, NH Specimen Size: 2.2 cm specimen. Massive chalcopyrite - "peacock ore" Field Collected: Cliff Trebilcock Catalog No.: A Cliff Trebilcock specimen Notes: |
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Species: PYRITE Locality: 110 Road Cut, W. Milan, NH Specimen Size: Octahedral pyrite crystals to 2.2 mm Field Collected: Cliff Trebilcock Catalog No.: A Cliff Trebilcock specimen Notes: Cliff has this labeled as "110 Road Cut, W. Milan, NH", but [tm] having visited this site, I think it is in Dummer, very close to the Milan town line. Octahedral pyrite is uncommon in NH. |
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Species: EPIDOTE Locality: Cambridge, NH Specimen Size: 10 mm field of view. Epidote crystals to 0.8 mm Field Collected: Cliff Trebilcock Catalog No.: A Cliff Trebilcock specimen Notes: Substrate matrix is milky quartz. |
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Species: SILVER - wire with Acanthite coating Locality: Mascot Mine, Gorham, NH Specimen Size: 2.5 mm field of view Field Collected: Cliff Trebilcock Catalog No.: A Cliff Trebilcock specimen Notes: |
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Species: MUSCOVITE Locality: Palermo Mine, N. Groton, NH Specimen Size: 0.6 mm spiky ball (largest) Field Collected: Unknown. Ex Pat Barker, gifted to Anna Wilken. Catalog No.: TBC Notes: I expected a phosphate, perhaps the spiky ball habit goyazite. An Oct. 2019 EDS (BC354A) gave K0.33Mg0.11Fe0.16Al2.34Si3O20 normalized for three Si. A second analysis from the same sample gave: K0..57Mg0.07Ca0.05Fe0.05Al2.68Si3O20.2 Following a review of the EDS data and photo, Jim Nizamoff suggested muscovite. The chemistry is reasonable. Jim said he had seen this muscovite habit in Maine pegmatites, but not from Palermo. |
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Species: FAIRFIELDITE-MESSELITE Locality: Palermo Mine, N. Groton, NH Specimen Size: 3.2 cm high specimen. Cream-colored fairfieldite-messelite with bronze childrenite and deep blue vivianite. Field Collected: R. Whitmore - 1965-1975 Catalog No.: u2246 Notes: Oct. 2019 EDS analyses, normalized for 2 Ca (BC256, BC256A) gave BC256A - Ca2(Mn0.36,Fe0.29)P2.2O5.2 BC256 - Ca2(Fe0.38,Mn0.26,Na0.02,Mg0.01,Sr0.01)P2.2O9 One analysis is Mn dominant (= fairfieldite) the second is Fe dominant (= messelite). These two analyses were on the same polished grain, about one mm apart. The BC256 analysis had tiny trace amounts of Mg, Na, and Sr. |