Mineral (Iron Ore)

Red Hematite

Iron(III) oxide (Fe2O3)

Limonite

Hydrous Iron Oxide (often Goethite FeO(OH), Lepidocrocite γ-FeO(OH), and other amorphous iron oxyhydroxides)

Specular Hematite (Specularite) in Matrix

Specularite (Fe2O3)

Limonite (Iron Ore/Hydrated Iron Oxide)

Limonite (mixture of FeO(OH)·nH₂O minerals, mainly Goethite, FeO(OH) and Lepidocrocite, FeO(OH))

Limonite (Iron Ore)

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

Limonite (Iron Stone/Goethite)

Limonite (mixture of hydrated iron oxides, primarily Goethite: α-FeO(OH))

Ferruginous Quartz

Quartz (Silicon Dioxide) with Iron Inclusion, SiO2

Iron (Hematite variety)

Iron (Fe) / Hematite (Fe2O3)

Hematite

Iron(III) oxide (Fe2O3)

Chalcopyrite in Quartz (Gossan/Iron Hat)

CuFeS2 (Chalcopyrite) with SiO2 (Quartz)

Yellow Ochre / Limonite

Limonite (FeO(OH)·nH2O)

Limonite (Yellow Ochre)

Limonite (an amorphous mixture of hydrated iron oxides, primarily FeO(OH)·nH2O)

Limonite (Ironstone)

Limonite (FeO(OH)·nH2O)

Limonite (Iron Ore Congcretion)

Limonite (a mixture of hydrated iron(III) oxide-hydroxides, FeO(OH)·nH2O)

Iron Ore / Ironstone Concretion

Mixture of iron oxide/hydroxide minerals, likely some combination of Hematite (Fe2O3), Goethite (α-FeOOH), and Limonite (a general term for hydrated iron oxides of variable composition) or potentially Bauxite (a mixture of aluminum hydroxides, often with iron oxides, (Al(OH)3) and FeO(OH)). The visual characteristics strongly suggest iron-rich material.

Quartz Vein in Host Rock (Gossanous Matrtix)

Silicon Dioxide (SiO2) with iron oxides (Limonite/Hematite)

Limonite Concretion

Limonite (FeO(OH)·nH2O)

Limonite (Ironstone Concretion)

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

Limonite (Ochreous)

FeO(OH)·nH2O (Hydrated Iron Oxide)

Limonite/Goethite on Shale

Hydrous ferric oxides (FeO(OH)·nH2O) often associated with argillaceous rock

Specular Hematite Geode/Nodule

Specularite (Polycrystalline Hematite), Fe2O3

Goethite/Limonite Iron Ore Node

Goethite (FeO(OH)) or Limonite (mixture of hydrated iron oxides)

Limonite (Yellow Ochre)

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

Ferruginous Sandstone (Gozzan)

Iron-rich clastic sedimentary rock with Limonite/Goethite

Specular Hematite

Iron Oxide (Fe2O3)

Limonite (Yellow Ochre)

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

Hematite

Iron(III) oxide (Fe2O3)

Limonite (Ironstone)

Hydrous ferric oxides (FeO(OH)·nH2O)

Hematite

Iron(III) oxide (Fe2O3)

Limonite (Ironstone Concretion)

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

Ferruginous Sandstone

Sandstone (arenite) with Limonite/Goethite cement

Specular Hematite

Specularite (Iron Oxide, Fe2O3)

Turquoise and Hematite

Turquoise (CuAl6(PO4)4(OH)8·4H2O) and Hematite (Fe2O3)

Sandstone (Ferruginous Concretion)

Ferruginous Sandstone Concretion / SiO2 with Fe2O3 cement

Limonite (Iron Stone/Gossen)

Limonite (FeO(OH)·nH2O)

Limonite with Iron Inclusions

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

Hematite

Iron(III) oxide (Fe2O3)

Ferruginous Quartz (Iron-stained Quartz)

Quartz with Iron Oxide inclusions (SiO2 with Fe2O3)

Limonite (Iron Ore)

FeO(OH)·nH2O (Hydrous ferric oxide)

Yellow Ochre / Limonite

Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)

Red Hematite (Iron Ore)

Hematite (Fe2O3)

Limonite (Iron Ore)

Goethite and related iron hydroxides (FeO(OH)·nH2O)