Natural piezoelectric effect may build gold deposits Ars TechnicaGold nugget formation from earthquake-induced piezoelectricity in quartz Nature.comEarthquakes can trigger quartz into forming giant gold nuggets, study finds Livescience.comElectric Sparks Generated Within Earth Might Be The Secret Behind Giant Gold Nuggets ForbesRadical Theory Suggests Earthquakes Spark Gold Nuggets Into Existence ScienceAlert