This small blue crystal is transparent, and seems to contain some kind of fog inside. While holding the crystal, you can speak the command word and begin recording yourself and your surroundings within 5 feet (or less if you so choose) until you speak the command word again.
A crystal containing a message automatically plays the message whenever a creature picks it up and mentally wished to view the recording. The crystal emits a light-based 3D projection of the speaker and their surroundings.
You can take 10 minutes with a filled crystal to empty it and ready it for recording again.