These fist-sized chunks of unworked stone are mirror images of one another.

These unremarkable-looking stones come in pairs. Once per day, the bearer of each stone can send a message (as the sending spell) to the bearer of the other stone. If a stone’s mate is not in a creature’s possession, no message is sent and you know the communication has failed. If either stone of the pair is destroyed, the other becomes useless.

Prerequisites: Craft Wondrous Item, sending.
Cost to Create: 500 gp (plus 400 gp for base item), 40 XP, 1 day.