Vodyanoi Amulet
From Witcher Wiki
"Made of stone and plant fibers, this amulet is a symbol of vodyanoi favor."
This is the amulet given to the woodcutters by the Vodyanoi in the Swamp in exchange for the sacrifice of Yaren Bolt's axe (which appears to be a Mahakaman 2-handed axe). Geralt must make this exchange by placing the axe on the Vodyanoi altar and waiting until midnight for their response.
