Fig. Par13c-f A view into the underground mining of “Paraiba”-tourmalines in the Heitor shaft (Batalha mining area, Paraiba, Brazil). The vertical shafts are driven to a depth of 40m in soft "kaolinized" pegmatites (Fig. Par13e-f). Underground tunnels are partially collapsed (Fig. Par13d). Picture Markus Paul Wild. P. Wild Archive.
Underground Mining of "Paraiba"-Tourmalines
