Infused dust is a crafting component in The Witcher 3: Wild Hunt that is needed to craft:
- All lesser glyphs
- Infused shard
- Lesser runestone
Crafting Requirements 
It can be purchased from the following merchants:
- All armorers and blacksmiths, except the one at Ardaiso Quarry
- Armors and weapons merchants in Nilfgaardian Army Group 'Center' Camp
- Merchant in the boatyard south of Refugees' Camp
- Merchant at Calveit Watchtower
- Merchant at Coast of Wrecks
- Merchant in Ursten
- Merchant by the road west of White Eagle Fort
- Merchant at the sawmill northeast of Rannvaig
- Merchant at the Isolated Hut on Hindarsfjall
- Merchant in Mohrin Village
- Merchant in Stacheier
- Ofieri merchant at Upper Mill
It can also be found as both random and guaranteed loot in Toussaint, and is a random drop from the following monsters:
Infused dust may also be obtained by dismantling:
- All runestones and non-lesser glyphs
- Infused shard
- Lesser runestone (crafting component)
- Gesheft (Land of a Thousand Fables)
- Grandmaster-level witcher gear chest armors and boots, except Forgotten Wolf School Gear