Smithing Stone [2] is a purple-colored stone used to upgrade a Rare (blue) rarity weapon to Epic (purple) rarity. These can only be found by killing a specific boss enemy within one of the mines ...

It's actually hard to complete an Expedition in Nightreign without tripping over at least a couple Smithing Stone 1s. They're a fairly rare drop from the breakable loot boxes. However, if you take the ...