Blizzard have acknowledged and are fixing the issue of 
Storm Dust scarcity. In a hotfix coming in the next few days, they are adding a new Shatter recipe for Enchanting. Players will then be able to break down 
Gleaming Shards into Storm Dust!
We’re working on a hotfix to address this.
The hotfix will add a new Shatter recipe to Enchanting, and the new recipe will let you shatter blue crystals and receive dust.
We expect this to become available in-game in the next couple of days.