I think this is an orthography issue rather than a phonology issue. I did a search in cmudict and found examples! sample → /s/ treasure → /ʒ/ visible → /z/

I think this is an orthography issue rather than a phonology issue. I did a search in cmudict and found examples! sample → /s/ treasure → /ʒ/ visible → /z/ unsure → /ʃ/ I could probably have thought of these eventually, but cmudict made it a whole lot quicker.