AM_Richterite_15 Formula: O22.4 (F1.6 Si7.76) Ti.24 Mg5 (Na Ca) K H.4 Name: Richterite Unit cell: 10.0166 18.0189 5.2871 90.0 104.908 90.0 , V=922.14 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 Rich62, Atomic parameters from ICSD