The title compound, digadolinium(III) oxidodisilicate, Gd2[Si2O7], was obtained in its M-type crystal structure after attempts to synthesize Gd5Br3[AsO3]4 as a by-product from fused silica ampoules. It crystallizes isotypically with M-type Eu2[Si2O7]. This structure consists of layers of ecliptically arranged oxidodisilicate [Si2O7]6− units separated from each other by bilayers consisting of GdIII cations.
