I don't have much to go on, but I keep thinking of this 80s scifi movie, and I can't recall what it was. All I remember is that it starts out (I think it's at the beginning) with a guy and his daughter mining some kind of crystals in a cave. They use some kind of tool to help extract them from the cave wall. Then some people come and capture them or something. Any ideas? I know it was on tv quite a bit because I'd watch it when I saw it on. I can't recall any other details though!