After Warehouse 9 agents bronzed Paracelsus, his brother, the Count, split the Philosopher's Stone, which Paracelsus had created, in two and took a tiny piece of the inner core of the stone so it could become the jewel of a ring. The ring became imbued with the power to return dead or dying plants to full health. The Count used this ring to entertain crowds of people.
In All the Time in the World, Paracelsus was unbronzed and stole several artifacts from the Warehouse, among them the ring. Paracelsus took the piece of the stone from the Count's ring and used it make the 2 halves of the Philosopher's Stone whole again. It's unknown if the ring still retains any of its properties now that the piece of the Philosopher's Stone which originally gave it its power is gone.