Hydrothermal synthesis of compounds in the fresnoite mineral family (Ba2TiSi2O8)

Crystals of Ba2TiSi2O8, Sr2TiSi2O8, and Ba2VSi2O8, all belonging to the fresnoite family were prepared by the hydrothermal method. Attempts to synthesize other members by substitution at the alkaline earth site, transition metal site, and tetrahedral site were not successful, but did lead to the formation of a variety of other mineral phases as well as the incommensurate structure, Ba2TiGe2O8. Structural studies on this compound and analysis of the other known fresnoite phases were performed to elucidate the nature of the incommensurate structure.