Lesser runestone is a crafting component in The Witcher 3: Wild Hunt that is needed to craft all lesser runestones. In the Hearts of Stone expansion, it is also needed to craft pyerog runestone and tvarog runestone.
Crafting Requirements 
It can be crafted, found as random loot in monster nests, or purchased from the following merchants:
- All blacksmiths except the one at Ardaiso Quarry
- All alchemists except Jonna in Rannvaig and the Freya Priestess on Hindarsfjall
- Weapons merchant in Nilfgaardian Army Group 'Center' Camp
- Merchant at Calveit Watchtower
- Merchant by the road west of White Eagle Fort
- Merchant at the Isolated Hut on Hindarsfjall
- Scoia'tael merchant in the forest south of Novigrad
- Zoltan Chivay during The Battle of Kaer Morhen (dependent)
- Merchant in Stacheier
- Runewright at Upper Mill