Just put to when you search for it, scroll all the way down until you see these weird names like to-xt-ty(Im guessing btw). You'll see shield eventually.
Cant you just keep all your questions in THIS TOPIC from now on? Just use the edit button, not only is it faster but it stops people flaming you and telling you to stop making topics.
Im pretty sure it takes around 2 minutes to mine 1 ore. I remember watching my friend, it took him close to an hour to get 1 full inventory cause he couldnt find any rocks.