AM_Fluoro-eckermannite_3 Formula: Si8 Mg6.12 V.02 Na1.81 O22 F2 Name: Fluoro-eckermannite Unit cell: 9.655 17.909 5.267 90.0 102.73 90.0 , V=888.34 Space group: C12/M1 (12)

Oberti R , Hawthorne F C , Camara F , Raudsepp M , American Mineralogist , 84 (1999) p.102-111, Unusual M3+ cations in synthetic amphiboles with nominal fluoro-eckermannite, composition: Deviations from stoichiometry and structural effects of the, cummingtonite component, Sample: V, Na.90Na.92Mg1.08Mg4.98V.02Si8O22F2