Epitaph stone
From Tardis Wiki, the free Doctor Who reference
Epitaph stones were used for communication by the Shansheeth. They were small shards of black stone which produced holographic messages, allowing the Shansheeth to give their condolences. The Claw Shansheeth used an epitaph stone when contacting Sarah Jane Smith on the "death" of the Eleventh Doctor. (TV: Death of the Doctor)
