Chalcedony
A type of quartz used by the ancient Egyptians to drive away ghosts, night visions and sadness. Chalcedony is never crystalline, but translucent and waxy in appearance. It usually is a smoky blue, but it may also be yellow or cloudy white. The Egyptians used it on their scarab seals.
Use Chalcedony in a sentence.
"Hey, isn't Chalcedony that guy that's gonna rat out Stone and Fen to the Erlkonig?"
Chalcedony.