Voolium
From Tardis Wiki, the free Doctor Who reference
A refined voolium crystal (blue, at front) and madranite one-five (green) in a psychic interference transmitter.
Voolium was a mineral abundant on the planet Calufrax, which, according to the Doctor, was the only place it was known to occur naturally.
The vibrations of refined voolium and madranite one-five crystals could used to power a psychic interference transmitter, and the presence of these two minerals brought Calufrax to the attention of the crew of the pirate planet Zanak, who needed it to neutralise the psychic powers of the Mentiads. (TV: The Pirate Planet)
