Locality: Playter Mine, Springfield, NH
Specimen Size: 2.6 cm specimen.
Field Collected: Bob Wilken (2010)
Catalog No.: 1824
Notes:
Locality: Turner Mine, Marlow, NH
Specimen Size: 9 cm specimen
Field Collected: A Friend
Catalog No.:
Notes:
Locality: Turner Mine, Marlow, NH
Specimen Size: 3.2 cm specimen
Field Collected: A Friend
Catalog No.:
Notes:
Locality: Turner Mine, Marlow, NH
Specimen Size: 3 cm specimen. Cluster of three terminated schorl-dravite crystals
Field Collected: A Purchased specimen
Catalog No.: 2016
Notes: Purchased as schorl, however these crystals have a definite brown tint under intense light, suggesting dravite. Much of the dark tourmaline from south western NH has been analyzed to be dravite.
Locality: Turner Mine, Marlow, NH
Specimen Size: 1.8 cm terminated schorl-dravite crystal
Field Collected: A Purchased specimen
Catalog No.: 2017
Notes: Purchased as schorl, however these crystals have a definite brown tint under intense light, suggesting dravite. Much of the dark tourmaline from south western NH has been analyzed to be dravite.
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: Rice Mine, N. Groton, NH
Specimen Size: 3.2 cm complete, double-terminated, schorl crystal
Field Collected: Leroy Grant - 1970's
Catalog No.: TBC
Notes:
Locality: Rice Mine, Groton, NH
Specimen Size: 2.2 cm, double terminated schorl crystal in quartz matrix
Field Collected: Leroy Grant
Catalog No.: 2134
Notes:
Locality: Founders Way, Amherst, NH
Specimen Size: 6 cm field of view, top photo
Field Collected: Peter Cristofono
Catalog No.: TBC
Notes: A 2023 EDS analysis (BC512a) indicated a tourmaline species with Fe >> Mg, but count values were too low to make a convincing species determination. EDS redo needed.