(Yb,Y,U,Th,Ca,Fe)(Nb,Ta)2O8
after the samarskite-(Y) redefinition (Britvin et al., 2019), with Fe as an essential and not substituting element, and considering data of Kjellman (2017), samarskite-(Yb) may either be a questionable species or a species stoichiometrically unrealated to samarskite-(Y)