I went on a tour of a disused gold mine near Dahlonega, Georgia (a town that sprung up due to the Georgia Gold Rush of the early 19th century). During the tour

I went on a tour of a disused gold mine near Dahlonega, Georgia (a town that sprung up due to the Georgia Gold Rush of the early 19th century). During the tour the guide pointed out little flecks of gold in the wall and mentioned that the property likely still had billions of dollars worth of gold in it, but the low hanging fruit had already been plucked, and the cost of extraction of the rest would be too high. That's pretty wild to me, that you can know where BILLIONS of dollars of gold is, but not get at it. On the other hand, thinking of how dangerous and expensive mining must be, it's not entirely surprising.