AM_Richterite_21 Formula: Si8 (Mg1.01 Ni3.99) Ca Na3 O24 Name: Richterite Unit cell: 9.8886 17.933 5.2525 90.0 104.461 90.0 , V=901.93 Space group: C12/M1 (12)

Della Ventura G , Robert J-L , Raudsepp M , Hawthorne F C , Welch M D , American Mineralogist , 82 (1997) p.291-301, Site occupancies in synthetic monoclinic amphiboles: Rietveld structure, refinement and infrared spectroscopy of (nickel, magnesium, cobalt)-richterite, Sample: Ni80