Beating the Wall of Flesh for the first time is one of the most exciting moments in any Terraria playthrough, but it also throws you straight into hardmode with a whole new set of rules, enemies, and resources to track down. Cobalt is the first tier of hardmode ore you’ll have access to, and it’s the building block for your first set of hardmode gear, tools, and weapons that let you take on early hardmode bosses. I remember my first hardmode run where I spent two hours swinging a gold pickaxe at shiny blue rock wondering why it wouldn’t break, so I put this guide together to save you that frustration. Knowing how to mine cobalt in Terraria is the first big step to getting a foothold in hardmode and progressing through the rest of the game.
Prerequisites You Need Before You Can Mine Cobalt in Terraria
You can’t just start hunting for cobalt as soon as you spawn into a new world, there are a few non-negotiable boxes you have to tick first. The first and most important is that you have to trigger hardmode by defeating the Wall of Flesh in the underworld. No amount of exploring will turn up cobalt ore before you beat this boss, because hardmode is the only game state that spawns this ore type.
Next, you need a tool with enough pickaxe power to break cobalt blocks. You need a pickaxe or drill with at least 65% pickaxe power to mine cobalt, and the only pre-hardmode tool that meets this requirement is the Molten Pickaxe. Gold and platinum pickaxes only have 59% pickaxe power, so they won’t even scratch cobalt blocks, no matter how long you swing them. If you got a Cobalt Drill from a shadow chest in the underworld before triggering hardmode, that works too, but most players will use the Molten Pickaxe for their first cobalt mining run.
Before you head out, you’ll also want to stock up on a few key supplies to make your run smoother and safer:
- Molten Pickaxe (or higher pickaxe/drill with 65%+ pickaxe power)
- At least 200 maximum health to survive hardmode underground threats
- Torches, glowsticks, or a spelunker potion to spot ore easily in dark caverns
- Featherfall or gravitation potion to avoid fall damage in deep, uneven cave systems
- A pre-hardmode weapon with at least 30 damage to fend off random hardmode enemy spawns
Best Locations to Find Cobalt Ore Spawns
Once you’ve triggered hardmode, you need to smash at least one Demon or Crimson Altar with a Hammer to spawn hardmode ores in your world. Each altar you smash spawns one of three tiers of hardmode ore, and the first tier is either cobalt or palladium, depending on your world seed. Cobalt only spawns if you get the blue first-tier ore variant when smashing altars – some worlds spawn palladium instead, so you can’t get cobalt in those saves without mods or creating a new world. If you smash three altars and don’t see any cobalt in your cavern layers, you’re likely playing a palladium world, and you can switch to mining that instead, as it has the same stat value as cobalt.
Cobalt ore spawns almost exclusively in the underground and cavern layers of your world, between 0 and -2000 depth, depending on your world size. It rarely spawns in the surface underground layer or the underworld, so you don’t need to waste time exploring those areas. You’ll have the most luck finding cobalt in the outer thirds of your world, away from the center where the underworld and jungle biomes are usually located. Veins are usually 10-30 blocks large, so if you spot one cobalt block, dig around the surrounding 5-10 blocks of stone, you’ll almost always find a full vein nearby.
Spelunker potions are the single best tool for finding cobalt fast. They highlight all ore blocks in a bright, glowing blue that’s visible even through solid stone, so you don’t have to dig random tunnels to find veins. Avoid mining cobalt near corruption, crimson, or hallow biomes early on, as the hardmode enemies in those areas will one-shot most players with pre-hardmode gear. Stick to neutral, uncorrupted caverns for your first few mining runs until you have better armor.
Step-by-Step Mining Process for Maximum Efficiency
Once you have your supplies and know where to look, you can start your mining run in a way that maximizes how much cobalt you get per hour. Start by picking a spot on the far left or right side of your map, about 1000 blocks away from the world center. Dig straight down until you hit the cavern layer – you’ll know you’re there when you start seeing regular lava pools and large, open cave systems instead of tight, narrow tunnels.
Chug your spelunker potion as soon as you enter the cavern layer, then start exploring horizontally instead of digging straight down. Horizontal exploration lets you cover far more ground than vertical digging, so you’re more likely to cross multiple cobalt veins in a single run. If you find a large natural cave system, follow it first, as exposed ore veins are far easier to spot and mine than veins hidden in solid stone.
When you spot a cobalt vein, don’t run straight to mine it right away. Clear all nearby enemies first, and place a few torches around the area to mark the spot and prevent new enemies from spawning while you mine. Don’t stop to mine every single cobalt block you see right away – mark the vein location with a colored torch, clear all nearby threats first, then go back to mine. This prevents you from getting jumped by a mimic or hardmode slime mid-mine, which can make you lose all the ore you’ve collected so far if you die.
Once you have 45 cobalt ore, head back to your base to smelt it into 15 cobalt bars at a furnace, then craft a Cobalt Pickaxe. This pickaxe has 100% pickaxe power and mines far faster than the Molten Pickaxe, so switching to it mid-run will cut your mining time almost in half. A pickaxe with the Legendary or Lucky modifier can give you up to 30% more cobalt per block mined, so reforge your tool before you head out if you have extra gold to spare. If you gather enough extra ore, you can craft a full set of cobalt armor, which gives you a 15% movement speed boost that makes exploring cave systems even faster.
Common Mistakes to Avoid When Mining Cobalt
Even with the right tools and locations, it’s easy to make simple mistakes that waste your time or get you killed. The most common mistake new players make is using a pickaxe that’s too weak. I’ve seen dozens of players spend 10 minutes swinging a gold pickaxe at a cobalt block wondering why it won’t break, and it’s always because they didn’t check the pickaxe power requirement first. Double check that you have a Molten Pickaxe or better before you head out, it saves you a lot of frustration.
Another common mistake is assuming every world has cobalt. As I mentioned earlier, first-tier hardmode ore is either cobalt or palladium, so if you smash multiple altars and don’t see any cobalt spawns, your world is a palladium world. You don’t need to keep digging for hours looking for cobalt that doesn’t exist, just mine palladium instead, it works exactly the same for crafting early hardmode gear.
Many new players also make the mistake of mining too deep, looking for cobalt in the underworld. Cobalt doesn’t spawn in the underworld at all, so you’re just wasting time running around lava pools and fighting demons for no reason. Stick to the middle of the cavern layer, where cobalt spawn rates are highest.
Never leave home without a decent weapon when you go cobalt mining – even a low-tier hardmode enemy can kill you in 2 hits if you’re still using pre-hardmode armor. Wraiths, hardmode slimes, and mimics spawn randomly in neutral caverns in hardmode, so you need to be able to defend yourself at all times. I always keep a Night’s Edge or a Molten Fury on my hotbar for my first cobalt runs, and I’ve avoided dozens of unnecessary deaths because of it.
Mining cobalt doesn’t have to be a frustrating, time-consuming process if you follow these simple steps. I still use this exact method every time I start a new hardmode playthrough, and I usually have a full set of cobalt armor and tools within an hour of beating the Wall of Flesh. Knowing how to mine cobalt in Terraria gives you the foundation you need to progress through early hardmode, take on bosses like the Destroyer, and work your way up to higher tier ores like mythril and adamantite. Next time you trigger hardmode in a new world, give these tips a try, you’ll be surprised how much faster you can get your first set of hardmode gear.