Hittel on Gold Mines John S. Hittell

Excerpt from Hittel on Gold Mines: And Mining of California

In quartz mining the auriferous rock is ground to a very fine powder, the gold in which is caught in quicksilver, or on the rough surface of a blanket, over which the fine material is Это и многое другое вы найдете в книге Hittel on Gold Mines (John S. Hittell)