(n.) Hydrous sesquioxide of iron, an important ore of iron, occurring in stalactitic, mammillary, or earthy forms, of a dark brown color, and yellowish brown powder. It includes bog iron. Also called brown hematite.

argentite arsenopyrite bauxite chalcocite cinnabar crude galena iron ore ironstone limonite lodestone magnetite mineral mineral-bearing material mispickel pyrite raw material rich ore rich vein rough diamond siderite stibnite unanalyzed mass unlicked cub untreated mineral virgin soil