"Now when a miner discovers a vena profunda he begins sinking a shaft and above it sets up a windlass, and builds a shed over the shaft to prevent the rain from falling in, lest the men who turn the windlass be numbed by the cold or troubled by the rain."
– Georgius Agricola, de Re Metallica
In order for ores to be smelted into metal, they must first be extracted from within the womb of the earth. Mining allows you to construct Mine Supports and to mine from softened rock and ore surfaces within the mine. Soften darker rock surfaces by lighting a fire by them and letting it burn.
Once you finish mining a cracked wall tile, your character will hold a large boulder which you can drop somewhere and then chip ore or rubble from it; alternatively the player can dump the boulder into a Stamp Mill for automated processing (you won't get Whetstones or Sterling Geodes this way).
Mine Special Conditions:
The purity of a ore is based on the level you are on and the distance from the ladder.
The Purity of the Ore Boulder transfers directly to the Bar of Pig Iron produced in the smelter. Purity also transfers to Bar of Copper, but has no effect in the game right now. The further from the Ladder you get your Ore Boulder, the better chance that it will have higher purity ore in it. If you wear clothing with a bonus to the Mining Artifice, you can get better chances for higher purity ore.
A cave in randomly collapses some mined out tiles around itself, replacing them with mineable tiles. They yield rubble boulders like normal grey tiles. When you mine you run the risk of triggering an impending cave-in, illustrated by dust falling from the mine ceiling. You can prevent the cave-in by building a Mine Support under it. You have in the ballpark of five to ten minutes to build a support before a cave in occurs.
The chance of triggering a cave-in is affected by:
There are 8 safe mine levels available for mining after creating a mine. The 9th level is known as the Dreamworld, it connects all other mines that have reached the 9th level and can be very dangerous to access. Caution is advised and one should think carefully before digging into the Dreamworld. Mining in level 8 might randomly result in a cave-down to level 9 (without mining black tiles).
In order to go down a level you must first find a dark tile. Dark tiles are randomly generated in the mine level so it is advised to use mining methods similar to MineCraft to find dark tile veins. Once a vein has been located you must prepare each tile by creating a pile of wood and lighting it on fire. Once the fire has burnt out, any wall that was directly touching the tile the fire was built on will become a standard, mine-able wall. You must then attempt to mine each tile in order to trigger a cave down. It is a random chance whether or not a tile will cause a cave down.
Once a cave down occurs your character will fall down to the next level and take significant blood damage. If you are KO'd due to this, you will not loose proficiencies, but you will drop your inventory. Be aware that the new level can contain bats which can be very dangerous in swarms or to new characters with low biles.
Mining a cave down will cause a mine entrance to appear and create a 13x13 hexagonal space around it. So before mining any dark tiles, it is advised to mine any surrounding ore.