Refined crystal structure of kuzmenkoite

The structure of the mineral kuzmenkoite found in the Lovozero massif (the Kola Peninsula) was reinvestigated by the X-ray diffraction analysis. This mineral belongs to the labuntsovite family and differs from other members o f this family by the absence of Na atoms, a high Mn content, and the new ty pe of filling framework channels because of the replacement of Na atoms by H2O molecules and H3O groups. It was found that the disorder of atoms in th e channels leads to lowering of the symmetry to Gin. (C) 2000 MAIK "Nauka/I nterperiodica".