The best way to make money in the past though, is even easier than that. Simply take ten pounds of aluminum ingots, and trade it to someone who deals in commodities straight up weight for weight for gold. They'd think they were getting a heck of a deal, and thus could be trusted to keep their mouth shut, and you'd be somewhat better off as well. Until the advent of electricity so separate aluminum from ore, it was insanely expensive stuff, and like gold, has the advantage of not being subject to tarnish.
Interesting!
Did you know there is still an ingot of aluminium (note the English spelling) amoung the British Crown Jewels? Before the turn of the 20th Century pure metallic Aluminium was that valuable it was considered a precious metal.