PAARAS
It is an imaginary stone (‘philosopher’s stone’), by the touch of which metals (iron, copper, bronze, brass etc.) turn into gold. This is just an illusion created by the priestly class in the mind of simple people. There can be no stone or any other thing that can perform such an action.
In Gurbaani, Paaras is used for the Guru and His Word or for God.
The Guru and his Word can transform an evil person into a noble person.
(Dr Harjinder Singh Dilgeer)