bituminous coal
often greasy, shiny, combustible organic sedimentary rock that consists of more than 75 per cent carbon by weight
en-GB/bɪˈtjuːmɪnəs ˈkəʊl/
en-US/bɪˈtumənəs ˈkoʊl/
often greasy, shiny, combustible organic sedimentary rock that consists of more than 75 per cent carbon by weight