This guide will help you with mining in Terraria.
This content is transcluded from Guide:Practical tips § Mining.
- With few exceptions, you should upgrade your pickaxe whenever possible: not only will better pickaxes mine blocks faster, but certain tiles (especially ores) can only be mined with stronger tools.
- The same goes for pickaxes/drills in Hardmode. They are mandatory for progressing to the next ore tier. The order is: Cobalt / Palladium, Mythril / Orichalcum, and finally Adamantite / Titanium. Adamantite and Titanium Ore should not be crafted into tools, as they do not unlock access to better ores.
- Do not jump down a large hole or cave without an extra jump, Umbrella, Featherfall Potion, Wings, or Lucky Horseshoe. If you do not have those, consider using Rope and platforms to safely descend.
- As a rule of thumb, you should not jump down terrain if you cannot see the glow of a torch or glowstick that you threw down without a way to stop falling.
- Use Spelunker Potions or throw Spelunker Glowsticks if you're unable to find anything of value: they highlight any valuable treasure and ores that are on your screen.
- Mining Potions and the Ancient Chisel increase mining speed directly.
- The Light modifier (and any other modifiers that increase the speed of the pickaxe/drill) will greatly increase the mining speed of tools.
- When the Minimap is expanded, hovering over an ore pocket will display its name next to the cursor.
- Pressing the Left Ctrl (pressing down the right joystick on Xbox) key changes your mining style to Smart Cursor, which is extremely useful for strip mining.
- You can descend relatively fast by auto-focusing the mining and digging a 2-block-wide shaft.
- Using Mining Armor is useful when mining. The helmet is especially useful as it mostly eliminates the need for torches.
- For quick trips to the various layers of the world, a hellevator can be a very useful structure. Dig a vertical shaft from underneath your base down to The Underworld and consider placing Ropes or platforms to conveniently ascend and descend (note that rope is faster).
- Do not look for Hardmode ores in the Underground Corruption, Crimson, or Hallow when you first start Hardmode unless you are very confident in your skill. Instead, if you have dug one, a hellevator is a good place to start looking.
- Hardmode ores cannot be found in all layers:
You can build shafts to connect disconnected caves. Build shafts if you can't proceed any further in the cave you're currently exploring, or as the safest way to explore them.
Digging through Water
If you're digging through water, you might drown and lose your coins. The safest method to prevent this is bringing along some Gills Potions or a Diving Helmet, or horizontally dig a tunnel of at least three tiles into the walls and mining the two tiles above the tunnel to create an air pocket. Additionally, as torches won't work underwater, consider bringing along some Glowsticks, Flare Gun or Cursed/Ichor Torches.
Once your tunnel is completely sealed off from the rest of the body of water, you'll need to drain the water inside of its walls. If there is a cave nearby, you can dig an outlet to let the water drain into that. Otherwise, dig a cavity off to the side starting from the bottom of your tunnel. If you are digging sideways, you need to place blocks behind you before digging through the water to prevent flooding your tunnels.
If you have access to the Pumps, you can use them to move water from it to any nearby cave or reservoir. Simply place an Inlet Pump at the lowest point of your tunnel and wire it to an Outlet Pump where you want it to end up. Attach a trigger such as a Lever to the circuit and use it to start to drain water.
Digging through Lava
No solid blocks can be placed in Lava, so digging through it can be a problem. If you need to dig through it, you can use obsidian skin potions which grant fire resistance to dig straight through the lava and move it to any nearby cave. Consider bringing a pickaxe that's capable of digging through Obsidian. Additionally consider bringing along some Gills Potions. Alternatively, Sand/Silt can be dropped into lava, and with enough, you can replace all of it with sand/silt. Bombs can also explode through lava and can easily be used for small-medium sized lava pits, especially when covered by obsidian.
If you don't have access to obsidian skin potions you can also alternatively flood your tunnels with water, so that there's enough of it to turn lava into Obsidian. Newly formed Obsidian will become the walls of your tunnel, and can be replaced by digging them and using another block. As the tunnel is likely to be flooded you may want to seek ways for breathing underwater, like the Gills Potion or digging an air pocket.
Traps can be found randomly while exploring, by using a Dangersense Potion, or by holding any wire-related item (for example, a Pressure Plate) or equipping a Mechanical Lens and looking for horizontal Wire lines. If the lines are short and not straight, it may be some explosives, Statues or Geysers. The Geysers can only be found in Lava layer.
These methods can also be used to find any Dead Man's Chests, as the chest is connected with wires around the traps.
Digging through the Underworld presents unique challenges, particularly in managing the lava spawned when Hellstone is mined.
Superheated Blood can make mining Hellstone extremely easy because it makes you completely immune to lava damage.
The fastest and easiest way is to use Obsidian Skin Potions, as you don't need to surround the Hellstone with blocks or move the lava. Furthermore, you can simply jump in one of the many lava lakes for easy access to the Hellstone. This will also prevent most monsters from reaching you. You can use a Magic Mirror to quickly escape before the buff ends.
Alternatively, you can completely surround the Hellstone veins with a layer of blocks. That way, when the Hellstone is mined, the lava it leaves will be safely contained. While standing outside the barrier, mine the Hellstone vein. If some Hellstone is out of reach, drain the lava into a reservoir or move it with Pumps.
A final though riskier option is to mine a small area under the Hellstone, and suspend yourself above the spawned lava with a multi-latching hook. This technique is sometimes faster but requires precise control of your position, and may make it difficult to reach veins in particularly inconvenient locations (such as those very close to a lava lake).
Other Tips for Mining Hellstone
Using an artificial Meteor biome
If the player places 50 pieces of Meteorite ore or more on the screen where they are mining, they can create an artificial Meteorite biome. In this biome, all monster spawns are replaced by Meteor Heads, which are more predictable, and tend to do less damage than the naturally spawning creatures of The Underworld. If the player can withstand the Meteor Head attacks, they can mine Hellstone in relative peace.
Using natural Underworld structures
There are often Hellstone ore veins next to the Ruined Houses, and with the thin wall of Obsidian Brick between the Hellstone, in which makes a great natural barrier. The player can mine most Hellstone ore veins, and if some of it is out of reach, mine a single block to drain the lake, as the house can function as reservoir.