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.
Locality: Dodge Gold Mine, Lyman, NH
Specimen Size: 2.5 mm crystal group, two views
Field Collected: Cliff Trebilcock
Catalog No.: u2280
Notes:
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.
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:
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:
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.
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.
Locality: Mascot Mine, Gorham, NH
Specimen Size: 2.5 mm field of view
Field Collected: Cliff Trebilcock
Catalog No.: A Cliff Trebilcock specimen
Notes:
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.
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.