Radium pyrosulfate would have the molecular
formula of RaS2O7 and the molecular weight of
402.1532 g/mol. However, there is no demand for this salt and it is not mentioned in the scientific literature.
It could be prepared by dissolving radium sulfate in
oleum and then heating the syrupy liquid to >150°C
to drive off the water:
RaSO4
+H2SO4 ? RaS2O7
+H2O