Elven stone

An elven stone is a magical artifact capable of long distance conversations if modified in the right way.

Background
Regalyan D'Marcall and Frenic claim they are of elven origin. The latter also says that it is a rare artifact and has to explain to Knight-Commander Martel the stone's magical properties meaning that the technique to manufacture these stones has been lost and only few of them still exist by the time of the Dragon Age.

Furthermore, the elven stone does not require magic in order to operate and it can be used by people who do not possess magical powers.