Dust 
is a special material created by breaking down enchanted armor and weapons in a disenchanting machine.
Only the Enchanter crafting class can use dust that comes in various tiers as follows:
Tier 1 - Twinkling Dust - used in level 1 Enchanter recipes
Tier 2 - Sparkling Dust - used in level 10 Enchanter recipes
Tier 3 - Shimmering Dust - used in level 20 Enchanter recipes
Tier 4 - Scintillating Dust - used in level 30 Enchanter recipes
Tier 5 - Glowing Dust - to be used in level 40 Enchanter recipes