If you stole all the gold in the world, all the gold that has been mined over the last 6000 years, and melted it down and cast it into a cube, that cube would be only 68 feet on each side. Easy to hide. Not so easy to move. All the gold still left in the ground would make a cube only about a quarter or a third of that size. Most gold things today are made not from gold fresh from the earth, but gold that used to be other gold things: a Roman ring, a Victorian candelabra, an Aztec scapular, a filling.