Citation: Li, T.-J.; Simonov, V.I.; Belov, N.V. (1966). The crystal structure of niokalite. Doklady Akademii Nauk SSSR, 167, pp. 566-569.
Formula: Ca6.5 Nb1.5 O18 Si4
Chemical name: Ca6.5 Nb1.5 (Si2 O7)2 O4
List type: noninterleaving
List: 2D
Basis: (0;1;0 0;0;1)
Dimensionality: 2
Formula: Ca6 Nb4 O34 Si8 (Ca3 Nb2 O17 Si4)
Multiplicity: 1