hi there! theres this guy on youtube that made an L rod that detects only gold and im fascinated! for my bad luck the guy speaks Arabic and i dont understand. that i understood is that you need 2 copper pipes, 2 wires, i think mercury and sulfur powder, and a battery. i m not sure about the mercury and sulfur i tried to translate some comments on the video. if you guys know please let me know. thanks! by the way its a 3-4 part video.