This question could be best dealt with by geologists or scientists versed in natural physics, but I would settle for someone just more knowledgeable than myself. There are a couple of paranormal video series that I have been following, that have created a question in my mind, particularly one called Ghost Mine. Since gold is often associated with the existence of quartz and paranormal theory is that ghosts are associated with unusual EMF, which can be produced by producing an impact on quartz, I have a theory I'm pondering... instead of impacts, can EMF be produced by simply placing quartz under continous or fluctuating high pressure, as I imagine occurs with deep quartz deposits? If so, that might explain a lot of what some people purport to be signs of the existence of ghosts and spirits. It could also explain why some disturbances of the Earth's magnetic field exist.