AM_Niobokupletskite_1 Formula: Mn5.65 Na.63 Zn.67 (Nb1.8 Ti.2) Si8 K1.78 Rb.13 O30.5 H4 Name: Niobokupletskite Unit cell: 5.4303 11.924 11.747 112.927 94.75 103.175 , V=669.50 Space group: P-1 (2)

Piilonen P C , McDonald A M , Lalonde A E , The Canadian Mineralogist , 41 (2003) p.27-54, Insights into astrophyllite-group minerals II: Crystal chemistry, Sample: MSH42, Locality: nepheline syenite pegmatite at Mont Saint-Hilaire, Quebec, Canada