| Vanadyl Dithionate, VOS2O6, is prepared by treating a solution of vanadyl sulphate with barium dithionate. It decomposes on standing, with evolution of sulphur dioxide. |
| A series of crystalline salts is known which resemble the ortho- and pyro-vanadates in composition, except that the oxygen is either wholly or partially replaced by sulphur. Copper orthothiovanadate, Cu3(VS4)2, occurs naturally as sulvanite. The following thio- and oxythio-compounds have been prepared. |