TY JOUR TI Dissymmetrization in eudialyte-group minerals. IV. Features of the blocky isomorphism in the structure of the Nb-deficient oneillite analogue in the frame of P3-symmetry KW eudialyte group KW oneillite KW crystal structure KW blocky isomorphism KW key sites KW primitive unit cell KW Mont Saint-Hilaire JO Vestnik of geosciences AU . Rastsvetaeva, R.K. AU Chukanov, N.V. AU Gridchina, V.M. AU Aksenov, S.M. PY 2024 IS 0 PB FSBI FIC "Komi Scientific Center of the Ural Branch of the Russian Academy of Sciences"