Althausite

Althausite is a relatively simple magnesium phosphate mineral with formula Mg₂(PO₄)(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.^[5][3][6]

Althausite
Dark reddish brown, subhedral crystals of althausite in a serpentine-talc matrix with dark gray subhedral hematite crystals and greenish lizardite
General
Category	Phosphate minerals
Formula	Mg2(PO4)(OH,F)
IMA symbol	Ahs[1]
Strunz classification	8.BB.25
Crystal system	Orthorhombic
Crystal class	Dipyramidal (mmm) H-M symbol: (2/m 2/m 2/m)
Space group	Pnma
Identification
References	[2][3][4]