As Jo noted Ge: Get

This is an apparent exception but, by and large, you'll find that the exceptions here will be Germanic words and the Germanic languages didn't go through that softening of Cs and Gs before Es and Is. The change was a purely a physical thing and didn't care that one word in a pair like magus/magi* underwent the shift and the other didn't. It's a matter of what the mouth was doing in the shift from the consonant to the vowel. In cases where the shift, for whatever reason, didn't happen (a word was coined after the shift had happened, for example) there will normally be some spelling convention to retain the hard sound as necessary, e.g. Italian spaghetti*.

* The things Ænigma will come up with. It wants spaghetti to be Spahn and magus/magi to be Maharashtra