Volnex VI was a planet once visited by the Sixth Doctor and Peri Brown.
The Javaman built his Dorganator machine on Volnex, using it to enslave the native Volnexians. He also used it to bring the TARDIS to Volnex.
Volnex appeared, at least in the area where the TARDIS landed, to be a planet of "rocks and sand", according to Peri. (PROSE: Turnabout is Fair Play)