text: FWIW, this is a very hard difference to spot in written text - your readers might not even notice unless you draw attention to it. (I speak BrE, and when reading the Mistborn trilogy by AmE writer Brandon Sanderson, in which the word aluminium is used a lot, I got as far as book 3 before even noticing the "aluminum" spelling - and when I did notice, I assumed it was a typo until noticing even later that it was consistently spelled that way.)
  @Randal'Thor For a Canadian perspective, I didn't even realize that there were two spellings until I was much older than I would care to admit. I always just thought there as a weird pronunciation tick when some people called it "aluminium". That "i" doesn't really stand out to me. When I see either word I immediately just think of the element regardless.
  99% of your readers won't notice one way or anohter
  Jan 22 '19 at 17:42
  Despite the standard existing, isn't Aluminum the one that came first, and first coined after criticism of a previous version and in not in the US? Thus IUPAC claiming Aluminium being the "more right" one is just pointless gate-keeping?
  @Trish: I got very confused - Sulphur is what we use... Then I looked it up and found that much like aluminium it is spelt differently in different places! :)
  Interestingly, Tolkien had to do something very similar for his spelling 'elven' instead of the then-common 'elfin' (as well as several other similar examples). Being a professor of philology, he knew better how the word should be spelled, and stood his ground. The form stuck.
  Jan 21 '19 at 22:01
  I'd be less confused by "aluminium" than I would by "metre" or "colour". "Aluminium" is pronounced differently from "aluminum" so it's easy to understand why that word was used (the character--or at least the author--speaks that way). If "metre" was used in an otherwise American-English text, I'd have no idea why that spelling was chosen since the words are pronounced exactly the same way.
  Of course, if it is fiction, and your American main character insists on saying "aluminium foil", you should be prepared for readers to eyeroll at the irritating character trait. (It would be slightly less weird if your main character is a chemist who's actually referring to the element rather than a beer can or other everyday item, and completely un-weird for a German writing a blog in their own voice.)
  Similar to Daniel, I would find "aluminium" less jarring than "metre" - I don't read every letter of every word and likely wouldn't even notice the extra "i" in aluminium, whereas "metre" screams British to me.
  Jan 22 '19 at 21:06
  This may be hard to pull off. I always read aluminum as alumnium. It took many seconds of eyeballing to figure out which one was which. I think you'd have to resort to something like aloo-min-um and al-u-min-e-um if the difference was narratively relevant.
  As an European (Dutch) with English learned as a second language, 'colour' and 'meter' do look right. As does 'aluminium'. It is how the words meter/metre and aluminium/aluminum are spelled in my own language while colour is what I have learned in school. Non native speakers may have different 'normal' from native speakers.
  Nov 22 '20 at 18:47
  It's true that "over two thirds of all native English speakers worldwide speak the American variety", but this is disingenuous, as there are plenty who speak fluent English as their second language. The total number of English speakers globally is 1.18 billion, with (in order) 283 million in the USA, 259 million within the European Union, 125 million in India, 92 million in the Philippines and 79 million in Nigeria. There are more English speakers in Germany (45 million) than in Canada (30 million)!
  @Chappo I wasn't saying that over half of all total English speakers speak AmE. I was just saying that it's kind of silly to say 'just' the U.S. and Canada use a particular spelling when that's over two thirds of all native speakers.
  @Chappo This isn't exactly the strongest data point, but I'm Canadian and I would spell and pronounce "aluminum" the AmE way. In general, I'd say our pronunciation matches AmE, and our spelling is split somewhat inconsistently between the English variants.
  Jan 22 '19 at 5:20
  @Chappo We would generally think of ourselves as using Canadian English. In some contexts/industries it will be closer to British English, and in others it will be closer to American English, but we have enough unique words, slang, and exceptions to the rules (from mashing the other English variants together) that our English is different from the other variants. See Wikipedia for a list of some of our uniquenesses.
  Jan 22 '19 at 6:22
  @camerondm9 Canadian generally uses the British spelling rules (or at least that's how they were teaching it like 10 years ago); but aluminum is a bit of the odd one out. We use the "American" spelling for aluminum for some reason. I'm totally okay with that though, since aluminum saves us a syllable while the usual spelling rules have no bearing on that.
  "Aluminum" is perfectly acceptable in a formal scientific context. It is unambiguous and officially accepted by IUPAC (unlike other alternate spellings like "sulphur" and "cesium"), so it is no less precise than "aluminium". Although strictly speaking what's acceptable is up to the journal editor.
  Fair enough. I disagree on the last sentence. It is not up to the editor to define nomenclature standards.
  @NofP The nomenclature Standard is aluminium, any publication by IUPAC reads Aluminium. It is however allowable to use aluminum and not have it rejected by other agencies.
  Jan 21 '19 at 20:19
  @Trish while I was taught to use Aluminium, following eyeballfrog comment I actually checked what are the common uses in the scientific chemistry community. It turns out that acceptable means synonym, and not a lower standard pubchem.ncbi.nlm.nih.gov/compound/aluminum atsdr.cdc.gov/phs/phs.asp?id=1076&tid=34 and scholar.google.co.uk gives ~300k results for aluminum in titles and ~180k for aluminium, with good peace for whatever acceptable means.
  Jan 21 '19 at 23:03
  @NofP America was supposed to start using "Aluminium" (the name given to the element in 1812, by the person who discovered it) as part of a deal with the IUPAC in 1990, whereby the rest of the world agreed to call Element 16 "Sulfur" instead of "Sulphur" (from the Latin "Sulpur"). Within 3 years, the USA had already reneged on their end, and the IUPAC basically said "sod it" and listed it as a "variant"...
  Jan 22 '19 at 20:30
  I prefer to use aluminium since only the United States (more like Divided States right now) uses aluminum. I see aluminum as the least true variant. However, since I live in the totally great country of called the United States of America, my laptop always tries to "correct" my spelling of aluminium, to aluminum, the improper spelling in my opinion.
  FuturePaleontologistFuturePaleontologist
  So to be clear, your answer to the question is, "no, it's never okay to use 'aluminium'"? Even though that's the spelling promoted by IUPAC?
  This could be a very relevant comment, but it doesn't actually answer the question.
  @F1Krazy - Correct
  According to my info, Thomas Young did 1812 a deliberate decision to propose the better sound of Aluminium. This spelling caught on better in the US and was used by virtually all US Scientists until the mid-1830s (at wich point aluminum became popular via culture and one dictionary) and was still dominant in science till 1895. IUPAC did explicitly forbid to use aluminum between 1990 and 1993.
  Check out the wikipedia talk page archives for aluminum, if you want to blow a few hours reading a holy battle. Neither side will ever admit they're wrong... especially the brits :)