Going deeper by meters, little by little, getting closer... closer...
[100 meters ahead has a 95% chance of Crystal Stone]
Finally, reaching twenty thousand meters deep, the surrounding scenery remains unchanged. Dim mine tunnels, solid rock walls, and occasionally the sound of winds blowing like sobbing.
On the rock wall a bit to the right, flashes of golden light jump out, and the Passive Skill of the Earth Mirror Book indicates the exact position. He turns his mining pickaxe and smashes towards it.
Before long, indeed, the smashed rock wall reveals a basketball-sized irregular glowing object embedded inside.
