AM_Combeite Formula: Na2.914 Ca1.543 Si3 O9 Name: Combeite Unit cell: 10.5 10.5 13.184 90.0 90.0 120.0 , V=1258.80 Space group: R-3M (166)

Ohsato H , Maki I , Takeuchi Y , Acta Crystallographica, Section C , 41 (1985) p.1575-1577, Structure of Na2CaSi2O6, Locality: synthetic high-temperature form