After mining out all the ore in several mines, I returned (after a month which should be plenty of time for the ore to re-spawn) only to find that I still can not mine the ore. I can tell that it has re-spawned because I can see that the coloration has returned, but I am not able to interact with the ore in any way. Why can't I mine the ore any more?
The coloration returning does not always indicate that it has fully replenished. It will return in due time. If you have already waited a month, it shouldn't be too much longer.
If an ore vein looks like it has ore to mine, but you cannot interact with it, you can leave the area and immediately re-enter it again, the veins will become minable.
I had the exact issue on my PS3, I just quit the game and went back on and I can mine it all now :) try quiting and re-opening the game, or restarting your console.
When I had this problem on xbox, I would just leave the mine or cave and then go right back in.
If you are using pc, go into thirdperson, enter console by pressing ~ (under escape) click on your character and type TAI.
Then type TAI again to enbale ai again. Then exit console and it should work.
You have a collision problem. I think the respawn is actually a week, but if you're on PC, just open console, select the ore vein, hit disable, then enable, and you should be able to mine. It's a glitch. Nothing you can do if you're on console, you'll just have to wait for a patch.
The colouration returned + can't use = Glitch. Try walking into it, you'll clip right through.
I had this problem too, I found that if you just attack the ore with your pick, you can mine it.