| Limonite (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. Thesaurus Entries 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 |