Wikipedia
Nabimusaite
Nabimusaite is a very rare mineral with formula KCa(SiO)(SO)OF. Its structure, as in case of similar aradite and zadovite, is a derivative of the one of hatrurite. Nabimusaite gives its name to nabimusaite group. The mineral was found in a pyrometamorphic rock of the Hatrurim Formation, a site known for the natural pyrometamorphism. It is supposed to be formed due to interaction of precursor assemblage with sulfate-rich melt. Nabimusaite is potassium- and fluorine-analogue of dargaite.