Methods of chemical preparation and crystallographic data are reported for two new condensed phosphates: a hydrated cyclotriphosphate with a formula MnNa4(P3O9)2 4H2O and its anhydrous form MnNa4(P3O9)2. MnNa4(P3O9)2 4H2O is monoclinic P21/a with the following unit-cell dimensions: a=8.536(2) Å, b=14.309(3) Å, c=8.508(2) Å, β=96.452(2)°, and Z=2. MnNa4(P3O9)2 is monoclinic C2/c with the following unit-cell dimensions: a=13.198(2) Å, b=8.241(1) Å, c=14.228(2) Å, β=95.045(1)°, and Z=4.