Copper Mine extraction speed.

I created 6 Copper Mines earlier and have checked them just recently. It seems two of them have been running with extraction times of 3 minutes and the other 4 only one minute. They are all level 3 copper mines. Is this a bug?

Oh, it's just the Quality mine shafts!

https://www.anony.ws/i/2015/10/28/CopperMine1.png

https://www.anony.ws/i/2015/10/28/CopperMine2.png

https://www.anony.ws/i/2015/10/28/CopperMine3.png

https://www.anony.ws/i/2015/10/28/CopperMine4.png

https://www.anony.ws/i/2015/10/28/CopperMine5.png

https://www.anony.ws/i/2015/10/28/CopperMine6.png

ive just found an other glich, the new geo that find 2 deposit show that both mines are bigger and can be mined faster, but only both of them is bigger but 2nd mine dont get the speed buf

For me, I have both mines at the larger size, but yes, only one of them is faster.

found that consentius geo glitch here too;
when he finds a second mine that "can be mined faster" that text is not real, the time for extraction is 3 minutes not 1.5.
Guild mates reported the same behaviour for their consentius geo.