Guide:Mining techniques

This guide will help you with mining in Terraria.

Shaft Mining
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 Potion or a Diving Helmet. Another option is horizontally digging 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.

When you come across water while digging downward, place blocks in the water where you want the walls of your tunnel. Sand and Silt can be useful here.

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, consider bringing a pickaxe that's capable of digging through Obsidian, as well as Obsidian Skin Potions and Sand or Silt. Additionally consider bringing along some Gills Potions.

This works much the same as digging through water, with the difference that lava can damage you. Sand or Silt blocks must be dropped into the lava in order to form the walls of your tunnel. If you want the walls to be made of some other material, drop them an additional block to either side, so you have room to place the permanent walls before reclaiming the temporary ones. You can then jump into the lava-flooded tunnel and drain the lava exactly as you would with water.

If you don't have protection from lava, you will have to tunnel around it and dig a reservoir to drain from your tunnels into it. Finally, connect the reservoir to the lowest part of the flooded section so that it drains completely.

Another way is to dig with the help of water. You need to 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. If you are doing this in the Underworld, water rapidly evaporates in it, so it must be replaced with Honey, which produces Crispy Honey Blocks instead of Obsidian.

Finding Traps
, although being the most common type of Traps, are somewhat rare. They can be found by using a Dangersense Potion. Alternatively, holding any wire-related item (e.g. a Wire Cutter) or equipping a Mechanical Lens and finding horizontal lines of wiring is another idea. 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 and the statues are often near Chests, which can be detected by a Metal Detector.

Mining Hellstone
Digging through the Underworld presents unique challenges, particularly in managing the lava spawned when Hellstone is mined.

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 could use a Magic Mirror to quickly escape before the buff ends, granted you don't die of fire damage.

Alternatively, you can surround the Hellstone veins completely 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.

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 Meteor 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, this 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.

Mining in Hardmode
In Hardmode, mining becomes more and more a trivial problem as pickaxes and drills with increasing Pickaxe power become available.

The post-Moon Lord is a flying mount which mines all blocks around the player within a certain radius at a very rapid speed. It is highly effective for most kinds of mining.