Pale coloured crystals (5-10 mm in length) from
small pockets in a pegmatite from Wolkenburg near Limbach-Oberfrohna,
described in Ertl et al.(2009). Image courtesy of Andreas Ertl.
Wolkenburg near Limbach-Oberfrohna, Saxony, Germany.
Tourmaline samples of the "fluor-elbaite"-rossmanite solid
solution series were chemically (including the light elements) and
structurally characterized for the first time. The crystal chemical
formulae of the X-site of these three investigated samples range from a
"fluor-elbaite" dominant composition with X-site = (Na0.65□0.29Ca0.06)
through X-site = (Na0.54□0.45Ca0.01)
to Na-rich rossmanite with the composition X-site = (□0.51Na0.48Ca0.01).
Ertl A, Kolitsch U, Meyer HP, Thomas L, Lengauer CL, Nasdala L,
Tillmanns E (2009): Substitution mechanism in tourmalines of the
"fluor-elbaite"-rossmanite series from Wolkenburg, Saxony, Germany.
Neues Jahrbuch fur Mineralogie - Abhandlungen, 186, 51-61.