(Museums Victoria) 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. To break open his find, Hole tried a rock saw, an angle grinder, a drill, even dousing the thing in acid. However,...