Difference between Copper and Iron-Mines

Goodmorning all,
I have an question.
What is the difference between the working form an Coppermine and an IronMine ?
I will explain why i ask this.
Everymorning i make 6 new Coppermines and 9 Ironmines.
I all all update them to level 2.
How can it be then some of my Coppermines , in the evening are depleted, and some of them still have more then 400 copper in it.
It is not the walking time, because every evening its 2 or 3 other mines.
And why are the Ironmines do it all right, they are all at the same time the same amount in it, and depleted one after another.

I hope you understand my question.
Orca45

are you using a geologist to find them that has the skill 'quality copper mineshafts'? with this skill the deposits will empty twice as fast, and as the skill is not always active for every deposit found, this will explain why only some empty faster than others. you can hover over each deposit found that has a gold wreath and see what skills they have.

iron mines do not have the option of a faster mine skill, so their empty rate will always be the same for all mines at the same level.

thanx kit that will help, I think you are right, never thought about that.

There is a skill to find larger copper mines too - but not every time. That could be a factor. Check the hovering golden symbol over some of the mines (you should have at least some) and also mouse over the find itself and you will see everything affecting that mine.