Psion orb
From Tardis Wiki, the free Doctor Who reference
Psion orbs were gemstones from Psion Castavares. The natives of the planet, who had no power of speech, used the gemstones to communicate telepathically.
Benek Chaloupka used a pair of Psion orbs in his magic act until one of them was broken. The other one ended up in the bottom level of 23rd century Prague and manifested the dreams of two children when they slept near it. (PROSE: Spoilsport)
