AM_Richterite_16 Formula: O22 F2 Si7.84 Ti.16 Mg5 (Na Ca) K Name: Richterite Unit cell: 10.0149 18.0099 5.2862 90.0 104.954 90.0 , V=921.17 Space group: C12/M1 (12)

Della Ventura G , Robert J-L , Beny J-M , Raudsepp M , Hawthorne F C , American Mineralogist , 78 (1993) p.980-987, The OH-F substitution in Ti-rich potassium richterite: Rietveld structure, refinement and FTIR and micro-Raman spectroscopic studies of synthetic, amphiboles in the system K2O-Na2O-CaO-MgO-SiO2-TiO2-H2O-HF, Sample Rich63, Atomic parameters from ICSD