Dravite gallery 2

DRAVITE Gallery Return to Dravite page. Click on image for larger view
Much of the black tourmaline in the western part of New Hampshire has been analyzed to be the Dravite species.
DRAVITE Wheeler Mtn., Winchester, NH 1.7 cm nearly equant dravite crystal.	Species: DRAVITE Locality: Wheeler Mtn., Winchester, NH Specimen Size: 1.7 cm nearly equant dravite crystal. Field Collected: Tom Mortimer Catalog No.: 540 Notes: Ideal dravite chemistry is: NaMg₃Al₆(BO₃)₃(Si₆O₁₈)(OH)₄ Dravite indicated by 2006 Bart Cannon qualitative EDS analysis. These Wheeler Mtn. dravite crystals were collected from an approximate one cubic meter milky quartz pod. These remarkably well formed dravite crystals were very difficult to expose from the quartz matrix and many were broken for those that survived whole. An October 2018 polished grain quantitative EDS analysis (BC310) gave an APFU from the tabulated element atomic percents as: Na_0.98Ca_0.27Mg_3.0Fe_2.78Al_16.74Si_15.99O_31.39 , normalized for 3 Mg. The Al and Si values are very high, but the ratios of Mg to Fe indicate this is magnesium dominant, suggesting a dravite identification.
DRAVITE Wheeler Mtn., Winchester, NH 2.2 cm group of three penetrating dravite crystals.	Species: DRAVITE Locality: Wheeler Mtn., Winchester, NH Specimen Size: 2.2 cm group of three penetrating dravite crystals. Field Collected: Tom Mortimer Catalog No.: 521 Notes:
DRAVITE Wheeler Mtn., Winchester, NH 5.3 cm specimen with 2 cm stubby, double terminated, dravite crystal in iron stained quartz.	Species: DRAVITE Locality: Wheeler Mtn., Winchester, NH Specimen Size: 5.3 cm specimen with 2 cm stubby, double terminated, dravite crystal in iron stained quartz. Field Collected: Tom Mortimer Catalog No.: 608 Notes:
DRAVITE Wheeler Mtn., Winchester, NH 2.5 cm specimen with 1.4 cm stubby dravite crystal in quartz.	Species: DRAVITE Locality: Wheeler Mtn., Winchester, NH Specimen Size: 2.5 cm specimen with 1.4 cm stubby dravite crystal in quartz. Field Collected: Tom Mortimer Catalog No.: 563 Notes:
DRAVITE Wheeler Mtn., Winchester, NH 1.2 cm specimen stubby, double terminated, dravite crystal on balsa pedistal.	Species: DRAVITE Locality: Wheeler Mtn., Winchester, NH Specimen Size: 1.2 cm specimen stubby, double terminated, dravite crystal on balsa pedistal. Field Collected: Tom Mortimer Catalog No.: 562 Notes: This crystal nicely illustrates the hemimorphic form of dravite crystals.
DRAVITE Wheeler Mtn., Winchester, NH 1.4 cm field of view. Interior of broken dravite crystal with cavity of brown dravite fibers.	Species: DRAVITE Locality: Wheeler Mtn., Winchester, NH Specimen Size: 1.4 cm field of view. Interior of broken dravite crystal with cavity of brown dravite fibers. Field Collected: Tom Mortimer Catalog No.: 559 Notes:
DRAVITE Wheeler Mtn., Winchester, NH 6 cm specimen with 2 cm stubby, double terminated, dravite crystal.	Species: DRAVITE Locality: Wheeler Mtn., Winchester, NH Specimen Size: 6 cm specimen with 2 cm stubby, double terminated, dravite crystal. Field Collected: Tom Mortimer Catalog No.: 725 Notes:
DRAVITE Wheeler Mtn., Winchester, NH 2.7 cm specimen with 1.5 cm stubby, terminated, dravite crystal.	Species: DRAVITE Locality: Wheeler Mtn., Winchester, NH Specimen Size: 2.7 cm specimen with 1.5 cm stubby, terminated, dravite crystal. Field Collected: Tom Mortimer Catalog No.: 723 Notes:
DRAVITE Wheeler Mtn., Winchester, NH 3 cm specimen with 2.1 cm stubby, terminated, dravite crystal in feldspar.	Species: DRAVITE Locality: Wheeler Mtn., Winchester, NH Specimen Size: 3 cm specimen with 2.1 cm stubby, terminated, dravite crystal in feldspar. Field Collected: Tom Mortimer Catalog No.: 724 Notes:
DRAVITE Canterbury Soapstone Quarry, Canterbury, NH 3.2 cm specimen height. Brown dravite tourmaline on quartz. DRAVITE Canterbury Soapstone Quarry, Canterbury, NH 7 mm zoom view, shows brown color	Species: DRAVITE Locality: Canterbury Soapstone Quarry, Canterbury, NH Specimen Size: 3.2 cm specimen height. Brown dravite tourmaline on quartz. 7 mm zoom view shows brown color. Field Collected: Tom Mortimer 2013 Catalog No.: 1882 Notes: From quartz outcrop near highway. EDS analysis indicated the Mg rich tourmaline dravite. The analyst stated, the EDS "detector detects Al better than Si so I�ll buy Dravite."
DRAVITE Vacinity of Soapstone Quarry, Richmond, NH 5 cm crude complete crystal	Species: DRAVITE NaMg₃Al₆(BO₃)₃(Si₆O₁₈)(OH)₄ Locality: Vacinity of Soapstone Quarry, Richmond, NH Specimen Size: 5 cm crude complete crystal Field Collected: Tom Mortimer - June 1977 Catalog No.: 1550 Notes: Collected from a pegmatite dike with Mike Undercofler. I was never able to find this dike again dispite several attempts. Dravite was indicated by a Canon Microprobe EDS analysis . Note the analysis plot shows Mg > Fe suggesting the magnesium dominant tourmaline dravite. An October 2018 polished grain quantitative EDS analysis (BC309) gave an APFU from the tabulated element atomic percents as: Na_0.23Ca_0.34Mg_3.0Fe_3.82Al_25.9Si_27.58O_22.5 , normalized for 3 Mg. The Al and Si values are very high, but the ratios of Mg to Fe indicate this is iron dominant, suggesting a schorl-dravite identification. These two EDS analyses illustrate the risks in reading too much into the relative peaks of an EDS plot result. The EDS detector used for the 2018 analysis has a superior light element detection ability over the 2006 analysis instrument. - - - - - - - More discussion added 4/4/24. The follow up EDS analysis with atomic % quantification (BC309 noted above) showed Fe > Mg, but also Ca > Na, suggesting the uvite tourmaline. A weight percent oxide analysis ia recommended. George Adleman (3/24) acquired a Raman analysis of the same polished grain as the BC309 EDS. This matched well with RUFF dravite plots.
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