A Riftstone is a very specific type stone with a connection to the Rift. Nobody is entirely sure where they came from or who made them but they are scattered all throughout the world. They are normally between 3 and 6 feet tall with a flat, slanted, and glossy side with runes carved on it. These runes glow when people approach.
Riftstones are used to summon Pawns from the Rift.