Whispering Sand

Sand, ash, or dust serves as a conduit for your conversation with other creatures in far-removed locales.
You fix in your mind the identity of the creatures with whom you wish to communicate (you must know, have met, or know the name of the targets), and then speak.
You know immediately which of the targets can respond, if any—if the targets possess the appropriate sandy focus (see below), or if the targets are located in areas of sand, dust, or ash, the spell functions; if not, it immediately ends.
Barriers and distance are not a factor, as long as both you and the targets have the appropriate focus and are on the same plane.
If contact is achieved, the sand whispers your messages back and forth for the duration of the spell, no matter your distance from each other, gleaning a message from a sound akin to wind on sand.
The spell does not transcend language barriers.
Focus: At least 1 pound of sand, dust, or ash.