AM_Lamprophyllite_2
Formula: Na Ca Mn.5 Fe Ti2.5 (Sr.667 Ba.667 K.667) Si4 O17.333 F.667 H.667
Name: Lamprophyllite
Unit cell: 19.431 7.086 5.392 90.0 96.75 90.0 , V=737.27
Space group: C12/M1 (12)

Saf yanov Y N , Vasil eva N O , Golovachev V P , Kuz min E A , Belov N V , Soviet Physics Doklady , 28 (1983) p.207-209, The crystal structure of lamprophyllite, Locality: Kola Peninsula, Russia