You're Digging This!

This will likely be one of your last achievements. You first need to get the first 4 pickaxes which you may have all the materials for by now if you've reset the world and killed It a few times.

Simple Pickaxe Copper Pickaxe Mithril Pickaxe Adamantine Pickaxe After you have obtained these 4 it's time to reset the world into a Nightmare world. Don't worry as you can always set it back to Normal difficulty at any time.
 * 4 Sticks
 * 3 Rocks
 * 3 Tough Grass
 * 2 Copper Bar
 * 1 Wood
 * 3 Mithril Bar
 * 1 Wood
 * 4 Adamantine Bar
 * 2 Ochre Bar
 * 5 Wood

Divine Pickaxe Large Cobalt Pickaxe
 * 8 Gold Bar
 * 4 Verdant Bar
 * 5 Wood
 * 8 Cobalt Bar
 * 4 Bronzed Bar
 * 5 Wood