Silver was a metal which, in human mythology, could be used to kill a werewolf, particularly in the form of bullets.
The First Doctor used silver bullets to kill Roberta Sampson, a werewolf. (PROSE: The Juror's Story)
Silver bullets were also utilised by the Brigadier to defeat the Destroyer. (TV: Battlefield)
Similarly, Rosa Caiman had a silver knife to defend herself against werewolves. (AUDIO: Loups-Garoux)
The planet Megerra was rich in valuable minerals such as silver. (PROSE: Shakedown)
Silver Daleks with blue domes were present on the temporary base the city of Andor on Moldox. (PROSE: Engines of War)
When forced to create EDTA to cure arsenic poisoning, Gwen Cooper used a number of ingredients in the antidote, one being silver. (TV: Rendition)
Silver had an atomic weight of 108 and high conductivity. (PROSE: Castrovalva)