NEW DATA ON MALLARDITE (NA2SIF6) DEPOSITED AROUND FUMAROLES OF THE GREAT TOLBACHIK FISSURE ERUPTION

Abstract

Samples of the material deposited around fumaroles were examined by X-ray diffraction on single crystals and polycrystalline aggregates and microprobe analysis. The material was found to contain a rare sodium silicofluoride, which was identified with a synthetic compound Na2SiF6. The morphology and a number of diagnostic features (cleavage, hardness, brittleness) of the mineral were examined. A new technique for chemical analysis of fluosilicates is proposed.