Mn-bearing "oxy-rossmanite" with tetrahedrally-coordinated Al and B from Austria: structure, chemistry, and infrared and optical spectroscopic study

Andreas Ertl

1Institut für Mineralogie und Kristallographie, Geozentrum, Universität Wien, Althanstraße 14, 1090 Vienna, Austria

George R. Rossman

Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125-2500, U.S.A.

John M. Hughes

Department of Geology, Miami University, Oxford, OH 45056, U.S.A.

Stefan Prowatke, Thomas Ludwig

Mineralogisches Institut, Universität Heidelberg, Im Neuenheimer Feld 236, 69120 Heidelberg, Germany



Rossmanite, with the ideal end-member formula [](LiAl2) Al6 (Si6O18) (BO3)3 (OH)4, a alkali-deficient tourmaline from Rožná, western Moravia, Czech Republic, was described as a new tourmaline by Selway et al. (1998). Hawthorne and Henry (1999) proposed “oxy-rossmanite”, with the formula [](Li0.5Al2.5) Al6 (Si6O18) (BO3)3 (OH)3O, as a hypothetical tourmaline end-member. No tourmaline composition has been described to date which can be assigned to “oxy-rossmanite”. Ertl (1995) determined lattice parameters together with qualitative chemical analyses of tourmalines from a moldanubian pegmatite, near the village of Eibenstein, Lower Austria (“Bunte Serie”). An Al-rich tourmaline (in colors red to pale-blue), with the lattice parameters a = 15.802-15.869 and c = 7.086-7.103 Å (determined by X-ray powder diffraction analysis), was originally assigned to olenite and elbaite by Ertl (1995), in the absence of quantitative chemical analysis and the absence of light element analyses. In this present article we provide detailed analyses of reddish Al-rich tourmaline (“oxy-rossmanite”) from that pegmatite, with structural, chemical, and spectroscopic data. A typical analysis of this tourmaline gives a composition ([]0.53Na0.46Ca0.01) (Li0.15Al2.38Mn0.29Fe0.04) Al6 (Si5.40Al0.41B0.19O18) (BO3)3 (OH)3.00 (O0.89F0.04OH0.07)


Pink "oxy-rossmanite" in the right center of a photograph of the specimen in matrix.