Crystal data for rhombohedral Pb₃[Ge₂O₇]isotypic with Pb-barysilite

Metastable barysilite-like Pb₃[Ge₂O₇] was obtained from the melt at a sufficiently high cooling rate together with stable Pb₅Ge₃O₁₁, α-PbGeO₃, and a homologous series of other metastable lead germanates. The crystal data derived from an indexed powder diagram are a = 10.2960(6), c = 39.805(4) Å, space group Rc, D_m = 7.18, and D_x = 7.188 Mg m⁻³ for Z = 18. The JCPDS Diffraction File No. for Pb₃[Ge₂O₇] is 33-1487.