AM_Helvine_2 Formula: Mn4 Be3 Si3 O12 S Name: Helvine Unit cell: 8.261 8.261 8.261 90.0 90.0 90.0 , V=563.76 Space group: P-43N (218)

Kudoh Y , Takeuchi Y , Zeitschrift fur Kristallographie , 173 (1985) p.305-312, The effect of pressure on helvite Mn8S2[Be6Si6O24], Locality: Schwarzenberg, Saxony, Sample: P = 14 kbar