I just arrived at a new place, and luckily me Mine skill and equipment was sufficient to mine the new ore. In the sweet spot, I hit for roughly 18-21 damage, in the right rhythm. Then I went to the village there, and bought a new charm, with more (magic) defence, but also +10 luck. Also I levelled up somewhere in between, so maybe that has something to do with it as well (I didn't spent the points).
Now the same ores are damaged up to 22 (and fairly often too). Is luck also taken into account when the damage is calculated? Or is it the level up that did the extra damage or (unlikely) the extra (magic) defence?