So when did deep mines become upgradable?? I just saw in another thread about adamant that you need it to upgrade your deep mines and I was like, "Upgrade, wha...?"
Anyway, I've been waiting a loooooong time for one of my deep mines to cough up a diamond so I can progress in the dragon quest line. Are they more likely to drop from upgraded deep mines? Could the fact that my deep mines are not upgraded have been keeping me from getting a diamond?