Crystal structure of new micalike titanosilicate—bussenite, Na2Ba2Fe2+[TiSi2O7][CO3]O(OH)(H2O)F

Abstract

The crystal structure of mineral bussenite, Na2Ba2Fe[TiSi2O7][CO3]O(OH)(H2O)F, found in the Khibiny massif (the Kola Peninsula) has been determined. The parameters of the triclinic unit-cell are a = 5.399(3) Å, b = 7.016(9) Å, c = 16.254(14) Å, α = 102.44(8)°, β = 93.18(6)°, γ = 90.10(7)°, sp. gr. $$P\bar 1$$ , R = 0.054 for 1418 reflections with |F| > 2.5σ(F). The mineral studied belongs to the family of layered titanosilicates, in which, unlike the sulfate-and phosphate-containing representatives of this family, the interlayer spaces are filled with carbonate groups.