Lockets of Communication

Magical communication is a regular occurrence in my world, though it still hard on the mages who perform the task.  One way to overcome some of the stress is the magical mirrors.  For those who have no talent for the arcane there are lockets of communication.  The name is deceptive, for the people involved can not actually talk to each other, but they can sense the other person wearing the matching locket.  Each person can feel the others emotions, such as being happy, sad, tired, etc.  They can tell how intense the emotion is and how far the person is away, but they can not tell why the person is experiencing the emotion or exactly where the person is.  These lockets are expensive and highly coveted by royals, but even the odd adventurer can find them separate or in pairs now and again in their travels.