'Muscovite' originates from English, specifically the word 'Muscovy' (an older name for the Grand Duchy of Moscow), ultimately from Russian 'Moskva' (Москва).

'Muscovite' changed from Medieval Latin/Latinized forms such as 'Moscovia' into Middle English forms like 'Muscovite'; from these forms the modern English 'Muscovite' (with variant spellings 'Moscovite' and less common 'Moscowite') developed.

Initially, it meant 'of or from Muscovy' (the historic state centered on Moscow); over time it evolved to mean specifically 'a native or inhabitant of Moscow' and was also applied to the potassium mica mineral now called muscovite.