=== Surface excavation ===
The first step in all mines is to make a mine entrance on the surface. This can be done on any [[cliff]] or [[rock]] tile. Surface mining is fairly quick compared to tunnel and ore mining. After 50 -60 mining actions, the message "You will soon create an entrance" will appear. A few actions later an entrance will be created. The exact value is random, averaging around 5.
Surface excavation will produce [[rock shards]] on some actions. The probability seems to be around 25%.