AM_Brannockite
Formula: K Sn2 Li3 Si12 O30
Name: Brannockite
Unit cell: 10.002 10.002 14.263 90.0 90.0 120.0 , V=1235.71
Space group: P6/MCC (192)

Armbruster T , Oberhansli R , American Mineralogist , 73 (1988) p.595-600, Crystal chemistry of double-ring silicates: Structures of sugilite and, brannockite