Amber is considered a valuable in The Witcher. In essence, this means it's not needed for any alchemical purposes. However, the druids in the swamp cemetery require it for their Green March and will exchange it for 3 willow potions.
- Wardrobe at the Reverend's house in the outskirts.
- Sometimes also upstairs at the house across the street from the Reverend's.
- Sometimes in the trunk next to Triss' bed.
- Sometimes on Dagon's body after the duel in Chapter IV.
- On Gramps' body if you choose to kill him in Chapter II.