Varos
Alien Worlds
Varos
Varos, a dusty red planet, was once a prison planet for the criminally insane, and is now home to the ComTec Mining facility. The only natural resource worth mining on Varos is the very rare and precious ore Zyton-7.
When the TARDIS ran out of Zyton-7 and stalled the sixth Doctor and Peri managed to use emergency power to reach Varos in the hope of obtaining Zyton-7, which ComTec Mining mines using the local Varosians.
Varos was being exploited by Sil, and was the subject of an invasion and takeover attempt by Sil and his Galatron Mining Corporation. The Doctor managed to halt the invasion after the GMC need became great, and Sil was order to pay any price for the Zyton. The Doctor was given some of the Zyton as a reward.