Corrupted Stone?

I finally got the recipe to make the map only to find that it needs corrupted stone. So… where do I get corrupted stone or make it??

Now that you have the Map Room recipe, look in your Firebowl Cauldron for the Corrupted Stone recipe.

I should have guessed. TYVM

Going to go hide in shame now.

I wouldn’t hide in shame. I do not think that is the obvious place when thinking of something called corrupted stone. Maybe I shouldn’t mention I spent at least an hour trying to “mine” for corrupted stones from various “dark” stones and mobs all around The Unnamed City. That was before trying different combinations of things in the furnace.