Manga Like Metallica Metalluca

In a world where rare metals drive the economy, "Minea", the people who seek out these metals at the risk of their own life, are highly respected. A strange boy called Ruka has wandered destructively into the failing town of Elza, declaring that his goal is to be a Minea! He ends up under the surveillance of a village girl, Shella, whose little brother is sick from a poison gas accident in the town's now-closed mine. But there may be more to this situation than meets the eye! Will Ruka be able to help his new friends, and maybe one day become a legendary Minea?