AM_Melilite_5 Formula: Na2.05 Ca5.95 Si4 O15 Name: Melilite Unit cell: 5.525 17.413 14.489 90.0 90.57 90.0 , V=1393.87 Space group: P121/C1 (14)

Armbruster T , Rothlisberger F , American Mineralogist , 75 (1990) p.963-969, Crystal growth and structures of mixed-anion silicates-germanates:, Ca5[(Ge,Si)2O7][(Ge,Si)O4] and Na2Ca6[Si2O7][SiO4]2, sample Na2Ca6Si4O15