Samarskite-(Y)

Samarskite is a radioactive rare earth mineral series which includes samarskite-(Y) with formula: (YFeFeU,Th,Ca)₂(Nb,Ta)₂O₈ and samarskite-(Yb) with formula (YbFe)₂(Nb,Ta)₂O₈. The formula for smarskite-(Y) is also given as: (Y,Fe,U)(Nb,Ta)O₄.

Samarskite crystallizes in the orthorhombic - dipyramidal class as black to yellowish brown stubby prisms although it is typically found as anhedral masses. Specimens with a high uranium content are typically metamict and appear coated with a yellow brown earthy rind.