Mineral (Iron Ore)

Specular Hematite Geode/Nodule

Specularite (Polycrystalline Hematite), Fe2O3

Limonite (Ironstone)

Hydrous ferric oxides (FeO(OH)·nH2O)

Hematite

Iron(III) oxide (Fe2O3)

Red Hematite (Iron Ore)

Hematite (Fe2O3)

Magnetite / Ironstone Pebble

Magnetite (Fe3O4)

Specular Hematite

Specularite (Iron Oxide, Fe2O3)

Limonite (Yellow Ochre)

Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)

Magnetite / Hematite mix

Magnetite (Fe3O4) and Hematite (Fe2O3)

Limonite Concretion

Limonite (FeO·nH2O)

Chalcopyrite (Peacock Ore)

Copper Iron Sulfide (CuFeS2)

Ferruginous Quartz (Iron-stained Quartz)

Quartz with Iron Oxide inclusions (SiO2 with Fe2O3)

Ferruginous Sandstone (Gozzan)

Iron-rich clastic sedimentary rock with Limonite/Goethite

Hematite

Iron(III) oxide (Fe2O3)

Limonite Geode (Ironstone Concretion)

FeO(OH)·nH2O (Hydrated Iron Oxide)

Yellow Ochre (Limonite)

Limonite (FeO(OH)wH2O)

Limonite (Iron Ore / Ochre)

Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)

Banded iron formation fragment (likely hematite–magnetite ironstone)

BIF; chiefly hematite (Fe₂O₃), magnetite (Fe₃O₄), and silica as microcrystalline quartz (SiO₂)

Specularite in Quartz

Specular Hematite (Fe2O3) in Quartz (SiO2)

Ironstone Concretion

Siderite or Limonite Concretion (FeCO3 or FeO(OH)·nH2O)

Limonitic Iron Ore / Goethite

Hydrated Iron(III) oxide-hydroxide (primarily FeO(OH)·nH2O)

Tiger's Eye (with Hematite/Magnetite matrix)

Pseudomorph of Quartz after Crocidolite (SiO2 with FeOOH/Fe2O3)

Botryoidal Hematite (Kidney Ore)

Hematite (Fe2O3)

Ironstone (Limonite/Hematite concretion)

Ferruginous Siltstone / Goethite (FeO(OH))

Ironstone Concretion

Ferruginous Siltstone/Ironstone (Fe2O3)

Limonite and Hematite Gossan

Hydrated Iron Oxide Mix (FeO(OH)·nH2O) / Ferric oxide (Fe2O3)

Hematite (likely Botryoidal or Specularite variant)

Iron(III) oxide (Fe2O3)

Magnetite-rich iron ore (probable magnetite schist)

Magnetite (Fe₃O₄) in a foliated metamorphic matrix, possibly magnetite–biotite schist

Limonite (Iron Ore)

FeO(OH)·nH2O (Hydrous ferric oxide)

Limonite (Iron Ore)

Hydrous Iron Oxide (goethite, lepidocrocite)

Gossan / Iron-Rich Weathered Rock

Hydrated Iron Oxides / Limonite / Goethite

Hematite / Jasper

Iron(III) oxide (Fe2O3) in Quartz (SiO2)

Hematite

Iron(III) oxide (Fe2O3)

Hematite

Hematite (Fe2O3)

Magnetite (Iron Ore)

Magnetite (Fe3O4)

Limonite with Iron Inclusions

Limonite (Hydrated Iron Oxide, FeO(OH)·nH2O)

Sandstone (Ferruginous Concretion)

Ferruginous Sandstone Concretion / SiO2 with Fe2O3 cement

Limonite (Ironstone Concretion)

Limonite (Hydrated iron(III) oxide-hydroxide, mixtures of FeO(OH)·nH2O)

Hematite

Iron(III) oxide (Fe2O3)

Ferruginous Sandstone

Sandstone (arenite) with Limonite/Goethite cement

Botryoidal Hematite (Kidney Ore)

Iron(III) oxide (Fe2O3)

Specular Hematite

Hematite (Fe2O3)

Ironstone Concretion / Limonite Specimen

Goethite and Limonite (Hydrous Iron Oxides)