What is "fluorellestadite"

n. (context mineral English) A rare nesosilicate of calcium, with sulfate and fluorine, belonging to the apatite group and forming a series with hydroxylellestadite.

Fluorellestadite is a rare nesosilicate of calcium, with sulfate and fluorine, with the chemical formula Ca(SiO)(SO)F. It is a member of the apatite group, and forms a series with hydroxylellestadite.