Mine

A mine is a special planet element. You can interact with it (left click) in order to get gold ore. This activity is called mining''. ''You can see if a player is mining if a mine is shaking next to him.

A mine exists in 4 states/steps : Mining is more efficient with a drill. It's quicker (see above) and you will get more ore : 2-3-4-5 units of gold ore per step instead of 1-2-3.
 * Steps 3, 2, 1 : Mining (left interaction) is possible, it takes a little less than 3 seconds without the drill, a little more than 1 second with it. The mine will go from Step N to Step N-1.
 * Step 0: The mine is exhausted. Wait 66 seconds and the mine will go from Step N to Step N+1.