What is "althausite"

n. (context mineral English) An orthorhombic-pyramidal gray mineral containing fluorine, hydrogen, magnesium, oxygen, and phosphorus.

Althausite is a relatively simple magnesium phosphate mineral with formula Mg(PO)(OH,F). It is very rare. Original occurrences are magnesite deposits among serpentinites. It is named after Egon Althaus (born 1933), a mineralogist at the University of Karlsruhe, Germany.