From Longman Dictionary of Contemporary Englishschistschist /ʃɪst/ noun [uncountable] HEGa type of rock that naturally breaks apart into thin flat pieces
Examples from the Corpus
schist• Near the waterline, the rushing waters have polished the schist to gunmetal, and carved it into fantastic flutes and chambers.Origin schist (1700-1800) French schiste, from Latin schistos (lapis) “stone that can be split”, from Greek, from schizein; → SCHISM 