User:Quercus solaris/Suffix -a for oxides

Suffix -a for oxides
Thus alumina is aluminum oxide.

Thus chromia is a chromium oxide (specifically, chromium(III) oxide).

Thus titania is a titanium oxide (specifically, titanium dioxide).

Thus zirconia is zirconium dioxide.

And since most element names that end in -um end, more specifically, in -ium, the -a for oxides often looks like -ia.

Is it an implicit requirement that this construction only works if the stem ends in a stressed vowel + -n/-m? Are there any extant instances that falsify that hypothesis?


 * [Later] I found an instance to falsify part of that hypothesis while upholding the core of it. It's not just a stressed vowel + -n/-m; it's also a stressed vowel + -s.
 * Thus magnesia is magnesium oxide.


 * [A few minutes later] I now see that this suffix pattern is covered at the oxide article in the nomenclature section (Oxide).


 * [A few years later] I now see that there is at least one exception to the regularity of the pattern: the word urania is polysemic and can refer either to uranium dioxide (the regular-pattern instance) or to any yellowcake, which usually contains various uranium oxides as well as other constituents.

Riffing around, it occurred to me to ask ...

Is Britannia an oxide of Britannium?


 * Then I linked the words and discovered via the link popup that there's something called Britannia metal aka britannium. So no, the oxide pattern doesn't apply, but it's interesting that these terms both exist and are related to each other.

Is unobtainia an oxide of unobtainium?

Is Polonia an oxide of polonium?

Is Lusitania an oxide of lusitanium?

Is Scania an oxide of scanium?


 * Is Scandia an oxide of scandium?

Is Romania an oxide of romanium?

Are crania oxides of my cranium?


 * [A few months later] I now see that a young Oliver Sacks once asked his Uncle Dave, i.e., Uncle Tungsten, whether *zincia was a valid instance of the pattern. Uncle Tungsten smiled and said he'd never heard that one used.