AM_Richterite_18 Formula: Si8 (Mg4.02 Ni.98) Ca1.09 Na2.73 O24 Name: Richterite Unit cell: 9.9073 17.978 5.2669 90.0 104.303 90.0 , V=909.03 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: Ni20