We must distinguish the nuggets found but melted (for obvious reasons transportability) nuggets that still exist in their original form.
First, the largest gold nugget ever found was the so-called « Welcome Stranger », it measured about 61 cm by 31. It weighed 109.6 kg out of earth, to 78 Kg (including 72 gold end) once melted and freed of impurities. It was discovered by John Deason and Richard Oates in 1869 in the state of Victoria in Australia at least ten centimeters from the surface! The fact remains today that two replicas, one belonging to the City Museum of Melbourne and the other in descending from John Deason, a monument at the place of its discovery, and a commemorative statue.