In 2015, David Hole was prospecting in Maryborough Regional Park near Melbourne, Australia.

Armed with a metal detector, he discovered something out of the ordinary – a very heavy, reddish rock resting in some yellow clay.

He took it home and tried everything to open it, sure that there was a gold nugget inside the rock – after all, Maryborough is in the Goldfields region, where the Australian gold rush peaked in the 19th century.