Black pearl dust is a crafting component in The Witcher 3: Wild Hunt that is needed to craft lesser runestone (the crafting component).
It can be obtained by dismantling black pearls, found as random loot, or 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
- Ducal Camerlengo in Beauclair