AM_Ferrarisite Formula: Ca5 As4 O25 H15.16 Name: Ferrarisite Unit cell: 8.294 6.722 11.198 106.16 92.94 99.2 , V=588.90 Space group: P-1 (2)

Catti M , Chiari G , Ferraris G , Bulletin de Mineralogie , 103 (1980) p.541-546, The structure of ferrarisite, Ca5(HAsO4)2(AsO4)2*9H2O:, disorder, hydrogen bonding, and polymorphism with guerinite, Locality: Sainte Marie-aux-Mines, Alsace, France