Board Thread:Off Topic/@comment-24993958-20151027072937/@comment-25396609-20151116232233

Dust mage is anyone who fills a role that is considered to be a mage, someone who utilizes dust and magic like skills.

As for how earth dust can be used; look at what Blake did, dust can be used to instantly generate the element in question, or to manipulate it more effectively, as with Weiss and the ice slide/fist.

Not as redundant as you might think.