We have no technology to do anything but small scale mining and construction on the moon. Even if the most expensive metals and minerals were available in their pure form laying on the surface, it would cost several times their worth to bring them back to earth. There is no water, fuel or air that is needed to process things into usable forms.
The reason we went to the moon in the first place was mainly to prove that we could in a dick measuring contest with the Soviet Union in the space race. We needed humans to operate the equipment but we might have been able to do it with robotic landers. Now we definitely have the technology to do it without humans. We learned a lot about the moon and the earth from the samples brought back but we found we didn't have much more to learn. The moon is basically a chunk of the earth so precious metals and minerals won't be any easier to find than they are on earth.