Abstract The synthesis and the structural characterization of tin niobates Sn 1+ x Nb 2O 6+ x , x=0.0, 0.5, and 1.0, are reported. The materials have been characterized by bulk chemical analysis, single-crystal and powder X-ray diffraction, and 119Sn Mössbauer and 93Nb and 119Sn solid-state NMR spectroscopies. SnNb 2O 6 is a synthetic analog of the rare mineral foordite. Red Sn 2Nb 2O 7 crystallizes in a pyrochlore structure with a=10.5386 Å. 119Sn Mössbauer reveals the presence of both Sn(II) and Sn(IV) in pyrochlore samples. 119Sn MAS NMR spectroscopy supports the presence in synthetic foordite of Sn(II) in eight-fold coordination. The six-coordinated Sn(IV) and eight-coordinated Sn(II) 119Sn MAS NMR resonances are not resolved in the Sn 2Nb 2O 7 pyrochlore spectrum. 93Nb NMR indicates a fairly distorted local environment for niobium in synthetic foordite, much more so than in the Sn 2Nb 2O 7 pyrochlore.