I'm not the person you're replying to, but actually, I didn't know that; I just went and read up the history of the word and it's pretty interesting (for a nerd like me), so thank you for highlighting this. I admit, it used to confuse/irk me to hear Americans pronouncing aluminium like aluminum, so it pleases me to realise that I was wrong and that Americans are actually just pronouncing aluminum like aluminum.

I think I didn't realise this in part because apparently aluminium is generally used in American scientific writing. This is interesting to me because many journals style guidelines demand American spellings of words (My mind blanks of specific examples right now, but I often have to replace s with z when Americanising my writing). I don't know why, but I find it neat to imagine a kinship with a hypothetical American scholar who curses as they "correct" aluminum to aluminium before submitting their paper.

Edit: I can't believe I literally wrote an example of a word with the relevant s/z thing and didn't notice. Americanise/Americanize