PARGASITE Gallery Return to Pargasite page. Click on image for larger view | |
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Species: PARGASITE Locality: Joppa Hill, Bedford, NH Specimen Size: 1.2 cm group of dark-green pargasite crystals. Field Collected: Tom Mortimer Catalog No.: U229 Notes:The EDS analysis plot has been reviewed by a well published mineralogist knowledgeable in the amphibole group. It is his opinion that this Joppa Hill amphibole is pargasite. An earlier analyst opinion was that this mineral was ferrohornblende, a close relative amphibole species. In 2022, George Adleman provided Raman spectra from a sample of this Joppa Hill pargasite. George sent Raman plots showing correlation with pargasite and ferro-pargasite: Raman plot 1, Raman plot 2. George stated: "This material produced a very noisy (low S/N) but readable Raman response...visually comparing the sample Scan450 to RRUFF Ferro-Pargasite & Pargasite, I believe both are present, with the Ferro-Pargasite possibly favored." |
Species: PARGASITE Locality: Joppa Hill Locale, Amherst, NH Specimen Size: 9 mm field of view Field Collected: Tom Mortimer Catalog No.: u2518 Notes: Collected from residential lot site off Pulpit Rd. |
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Species: FERRO-PARGASITE Locality: Joppa Hill, Bedford, NH Specimen Size: 3.5 cm specimen Field Collected: Tom Mortimer - '90 Catalog No.: 734 Notes: EDS analysis (BC489) of these dark blades was indefinite as to if this is ferro-pargasite or ferrohornblende. A small noisy peak at about 1 KeV for sodium (required for ferro-pargasite) was unmarked. Ferro-pargasite chemistry is: NaCa2(Fe4Al)Si6Al2O22(OH)2 . The chemistry computed from this BC489 analysis is: Ca2.94Fe4.22Mg1/10Al1.92,Si5.93O23 normalized for 23 O. Ferrohornblende, Ca2[Fe2+4(Al,Fe3+)](Si7Al)O22(OH)2 , has a similar element content, but Na is not included. Magnesiohornblende forms a series with ferrohornblende, with Mg replacing Fe. So this may be ferrohornblende with some magnesiohornblende component. A Raman analysis of a similar Joppa Hill specimen favored ferro-pargasite. A photo of the meionite-scapolite crystal on this #734 specimen is in the scapolite gallery. The Joppa Hill locality sits on the Amherst-Bedford town line. This specimen came from the Bedford side. |