Batievaite-Y is a new mineral from the rosenbuschite group: Y-analogue of hainite from nepheline-feldspar pegmatite of the Sakharjok massif (Kola Peninsula). Mineral is triclinic, sp. gr. P-1, unit cell parameters a=9.4024, b=5.5623, c=7.3784 Å, α=89.919, β=101.408, γ=96.621º (R1 = 0.057). Occurrence Y (substitution Ca) in considerable amounts (2.5 times higher than for the previously described minerals) causes significant structural changes. Some of the cationic and anionic positions in the structure are substituted by water molecules, that is possible due to the presence of vacancies in the octahedral layer.