ironstone
ferruginous rock containing one or more distinct natural chemical compounds from which metallic iron may be profitably extracted. The chief ores of iron consist mainly of the oxides: hematite ...; goe, rauamaagid - looduslikud rauatoorained, maavarad. Tähtsamaid rauamaake moodustavad mineraalid on magnetiit, titanomagnetiit, hematiit, götiit ja sideriit; rauamaagi aheraine sisaldab kvartsi, silikaat