Whetstone

Whetstone can be found in bandit camps. Hover over yellow areas on the map to see what resources will drop from each camp.

After killing Grayson the Armourer (Level 27), you will unlock the recipe to create Whetstone.

Crafting
1x Copper Ingot

12x Stone Dust (9x with floor bonus)

Building: Furnace

Recipes
Minor Explosives Box: 8x Sulphur, 8x Plank, 4x Whetstone

Merciless Copper (Weapon): 1x Copper (Weapon), 2x Crude Sapphire, 6x Whetstone, 3x Leather