IPA: /ˌmɪnəˈrɑːlədʒɪst/
KK: /mɪˈnɛr.əl.ə.dʒɪst/
A person who studies minerals and their properties.
The mineralogist examined the rock samples for their mineral content.
Mineralogist → It is formed from "mineral" (from Latin *mineralis*, meaning pertaining to minerals) and "-ogist" (from Greek *-logistēs*, meaning one who studies). A mineralogist is someone who studies minerals.
Think of a person who studies 'minerals' — that's what a mineralogist does, as the suffix '-ogist' indicates a person who studies a specific field.
No commonly confused words.