AM_Harstigite Formula: Ca6 Mn Be4 Si6 O24 H2 Name: Harstigite Unit cell: 9.793 13.636 13.83 90.0 90.0 90.0 , V=1846.82 Space group: PNAM (62)

Hesse K F , Stumpel G , Zeitschrift fur Kristallographie , 177 (1986) p.143-148, Crystal structure of harstigite, MnCa6Be4[SiO4]2[Si2O7]2(OH)2, Locality: Harstigen mine, Sweden