There are currently 3 Teleport Stones in the game.
Teleport Stone Central:
Brings you back to your sleeping chamber. Received from Trey at the sleeping chamber.
Teleport Stone Begus:
Brings you back to the capital of Begus. Received from Elly when finishing her recruitment quest.
Teleport Stone Amagal:
Brings you back to the Yin Tower in Amagal. You receive it after meeting the Magespirit, which follows the thief girl events in Parverhill.