AM_Richterite_31 Formula: Si8 Mg5 (Ca1.6 Na.4) K.4 O24 Name: Richterite Unit cell: 9.9548 18.021 5.2735 90.0 104.724 90.0 , V=914.98 Space group: C12/M1 (12)

Hawthorne F C , Della Ventura G , Robert J-L , Welch M D , Jenkins D M , American Mineralogist , 82 (1997) p.708-716, A Rietveld and infrared study of synthetic amphiboles along the, potassium-richterite-tremolite join, Sample: Kr40