USA
Maine
Oxford County
near Rumford
Black Mountain Pegmatite
 

 

No image available at this time.

Elbaite and rossmanite occur in the outermost zones of the Black Mountain pegmatite, Maine. The identification has been determined through electron microprobe analysis. The rossmanite occurs as pink crystals in a lepidolite pod in the 2nd intermediate zone of the pegmatite.
 

Composition:

([]0.55Na0.45) (Li0.96Al1.94 Mn0.06Zn0.03Fe0.01) Al6 (Si5.84B0.08Al0.06O18) (BO3)3.00 [(OH)3.52F0.28]
 

Cell parameters (Ertl & Hughes, pers. com.)

a  = 15.803
c =   7.092

References:

Brown, C.D. and Wise, M.A. (1991) Mineralogy and internal structure of the Black Mountain pegmatite, Oxford County, Maine. Geological Society of America Annual Meeting, Abstracts with Programs, A329.

Dyar MD, Taylor ME, Lutz TM, Francis CA, Guidotti CV, Wise M (1998) Inclusive chemical characterization of tourmaline: M÷ssbauer study of Fe valence and site occupancy. American Mineralogist 83, 848-864. [samples 45 and 46, labeled olenite, are actually rossmanite].

Wise, Michael A. (2000) Geochemical evolution of tourmaline in the Black Mountain pegmatite, Maine. GeoCanada 2000--The Millennium Geoscience Summit, Conference, Calgary, AB, Canada, May 29-June 2, 2000, 622-625. Publisher: GeoCanada 2000, Calgary, Alberta  http://www.cseg.ca/conferences/2000/825.PDF

Main Department of Conservation. Tourmaline: Maine's State Mineral.