I can't remember what Superman film it was, but there is a scene where Superman gets a lump of coal, squeezes it really hard and turns it into a diamond for Lois.
I thought, why don't people get one of those car crushing machines and then fill it with coal, you'd be loaded!
A childhood belief about chemistry

others believed things like this
- i used to believe that coal from stockings was santa's poop because i was bad— dylan mcdonald
- I used to believe that the Lehigh tunnel in Pennsylvania was created by Superman.— Holz
- I used to believe that I could fly like Superman if I had the right cape and got a good running start. — Rick
- I always wanted to use the telephone to call Jesus, Santa and Superman— Alex Burghart
- My friend managed to convince a gulliable kid at various stages of school that he was superman and a robot.— naff
- My mom told me when i was little, that the Easter bunny and Superman lived togethor in Detroit at the park. — someone