This Core Keeper guide will tell you that exactly. You’ll need at least a Tin Pickaxe to start mining Iron Ore since the stone walls and ore itself are both rather sturdy.
How to Get Iron Ore in Core Keeper
Like the Clay Caves and the Tin Ore they hold, you may have stumbled on the Forgotten Ruins biome with Iron Ore early on and chosen to leave it for a later time. That’s because the Forgotten Ruins biome is far more perilous than the Clay Caves and the default dirt biome.
The location of the Forgotten Ruins is, like everything else in Core Keeper, random. We have found that specific areas tend to be separated by cavernous ravines at most points, though not always, so it’s good to keep an eye out for the area’s tell-tale signs.
The stone walls of the Forgotten Ruins are grey and the fireflies are blue (as opposed to yellow variety in the base biome). It’s easy to tell you’re in the right place for mining Iron Ore, even if the game doesn’t outright tell you.
Iron Ore can be found in the walls of the Forgotten Ruins just like any other ore; a sparkle indicates its location. Be wary of the enemies found in this area, though: you may want to bring at least a Tin Sword along to defend yourself.
That’s all you need to know about where to find Iron Ore in Core Keeper. Now that you have some in your inventory, you can start smelting Iron Ingots, moving up the crafting chain to making better, stronger items. Iron Ore is certainly not the last metal you’re going to need, though. Check out our other Core Keeper guides here on GameSkinny for more tips, tricks, and locations articles.