Got my miner up to level ten, and I notice in the mining in interface, where it llists the available deposits, it says, for example,
Copper ore -
100% (chance of gathering), then below that there's a symbol with the number 15% next to it. What is that 15% and the symbol next to it? I assume it means I have a 15% chance of gathering a special kind of copper ore? What's so special, about it?