Ruby
From Tardis Wiki, the free Doctor Who reference
Rubies from Venus were among the treasures kept in the Dalek Treasure House on Skaro. (COMIC: Treasure of the Daleks)
Fatima told El Akir where Barbara Wright was hiding for the price of a ruby ring. (TV: The Crusade)
The Toymaker had rubies on the silver collar of his Chinese Mandarin outfit. (PROSE: The Celestial Toymaker)