That is still impossible. It is not how mining works. You can't easily high-grade old mines, and even if you could, the grade is not enough to do so. Especially ones that offer absolutely no access. You just can't wander in the old workings, spot a obvious high-grade vein and "mine" it by hand.
What you claim is absolutely ridiculous and defies even basic the most basic elements of geology.
News 
Market Data 
Discover 
