Sending Stones

Sending Stones come in pairs, with each smooth stone carved to match the other so the pairing is easily recognized. While the user touches one stone, they can use an action to cast the Sending spell from it. The target is the bearer of the other stone. If no creature bears the other stone, the sender knows that fact as soon as they use the stone and the spell is not cast. Once Sending is cast through the stones, they can't be used again until the next dawn. If one of the stones in a pair is destroyed, the other becomes non-magical.