These ferric hydroxides commonly include goethite (FeO-OH) and so-called "amorphous ferric hydroxide" or limonite. Bog ore often combines goethite, magnetite, and vugs or stained quartz. The main iron ores are from the oxide group consisting of hematite, goethite, and magnetite. The natural ores are mainly mixtures of hematite and goethite. It is associated with magnetite, ilmenite, anatase, pyrite, marcasite, lepidocrocite and goethite. This is a chert containing oxidized iron in the form of hematite and goethite. Oranges and browns are attributed to hematite or goethite. In general, bog ores consist primarily of iron oxyhydroxides, commonly goethite (FeO(OH)). The goethite crystals are stable and well formed for a biogenic crystal. He was fascinated by mineralogy, and the mineral goethite (iron oxide) is named after him. Spirit rover discovered sulfates and goethite in the Columbia Hills. Submicron-sized goethite [FeO(OH)] is yellow; coarse goethite is brown. After one to two days, these ions are converted to goethite crystals. Fine goethite specimens are rare and therefore are valued collectibles. The most prominent metal by percent composition is iron in the form of goethite.