German Quarz, from Middle High German twarc, probably from a West Slavic language (compare Czech tvrdý (“hard”), Polish twardy (“hard”), Russian твёрдый (tvjórdyj, “hard”)), from Old Church Slavonic тврьдъ (tvrĭdŭ, “firm”), from Proto-Slavic *tvьrdъ.
- (mineralogy) The most abundant mineral on the earth's surface, of chemical composition silicon dioxide, SiO2. It occurs in a variety of forms, both crystalline and amorphous. Found in every environment.
quartz m (plural quartz)