So my basic question is this: Would it be possible that Aluminium could have been discovered earlier than it was (that is, the purer aluminium discovered in the 1800s)? What other technologies would enable such a thing to occur? My theory is, that given use of Magic in fantasy worlds, would someone be able to use lightning magic to perform the electrolytic part of aluminium creation? I am aware that Aluminium itself doesn't have as many applications in a medieval technology era, because it's not as hard or as strong as steel, but it is really light, and shiny, and the oxide layer that appears in contact with air would protect it. My theory is this: Would the earlier discovery of such a metal make it suitable for use in currency? When Aluminium was first discovered, I understand that it was used for decorative pieces, since it was lightweight, and shiny. You could coat heavier metals in a layer of aluminium to make coins of different values. The heavier the coin, the more its worth. Limited availability of lightning magic,coupled with the required knowledge to perform the task would make it easy to control the amount of it in the system. Can anyone think of any problems with this?