AM_Pargasite_56 Formula: Na Mg4 Al3 Ca2 Si6 O24 H2 Name: Pargasite Unit cell: 9.893 17.937 5.2802 90.0 105.518 90.0 , V=902.82 Space group: C12/M1 (12)

Welch M D , Knight K S , European Journal of Mineralogy , 11 (1999) p.321-331, A neutron powder diffraction study of cation ordering in, high-temperature synthetic amphiboles