Austria
Lower Austria
Eibenstein an der Thaya
Marble quarry


Fragments of "oxy-rossmanite" about 200 μm in size.

 

Occurrence:

Rossmanite was found northeast of Eibenstein an der Thaya in a pegmatite where only a marble quarry now remains. This locality is about a km away from an olenite pegmatite that was described in Ertl et al. (2003). Only one crystal of rossmanite from this locality is known to exist. It was collected after the pegmatite was mostly mined out. The crystal is in a private collection in Europe and is about 5 mm diameter. The crystal grades from green into red and pink and has a thin dark outer zone visible in the image above. A few fragments less than 1 mm in diameter were removed for detailed scientific study. The chemical analyses obtained as part of this study led to the identification of a hydroxy-deficient rossmanite. This may be a new mineral species that corresponds to the hypothetical mineral named oxy-rossmanite in the tourmaline classification scheme of Hawthorne and Henry (1999).

Composition:

([]0.53Na0.46Ca0.01) (Al2.37Mn0.25Li0.33Fe0.04Ti0.01) Al6 (BO3)3 [Si5.47Al0.28B0.25O18] [(OH)2.85 O0.15] (O0.86H0.10F0.04)

 

X-site occupancy

 

The aluminum content in the Y-site exceeds the amount of the ideal rossmanite composition (LiAl2) and moves the composition in the direction of ideal "oxy-rossmanite", Li0.5Al2.5.

 

Publications:

Ertl A, Rossman GR, Hughes JM, Prowatke S, Ludwig T (2004) Mn-bearing "oxy-rossmanite" with tetrahedrally-coordinated Al and B from Austria: structure, chemistry, and infrared and optical spectroscopic study. American Mineralogist 90, 481-487.

References cited:

Ertl A, Hughes JM, Prowatke S, Rossman GR, London D, Fritz EA (2003) Mn-rich tourmaline from Austria: structure, chemistry, optical spectra, and relations to synthetic solid solutions. American Mineralogist 88, 1369-1376.

Revised 8-Jun-2014