Mineral (Iron Ore)

Ironstone Concretion (Nutstone)

Ironstone (with High Limonite/Hematite Content)

Bauxite

Bauxite (mainly Al(OH)3, AlO(OH))

Iron Ore / Hematite Rock

Iron oxide (primarily Hematite, Fe2O3)

Hematite

Iron (III) Oxide (Fe2O3)

Hematite

Iron(III) oxide (Fe2O3)

Hematite

Iron Oxide (Fe2O3)

Gossan (Iron Hat)

Iron oxide-rich weathered rock (primarily Limonite and Goethite with secondary Quartz)

Red Jasper (Oolitic Hematite)

Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) impurities

Hematite

Iron Oxide (Fe2O3)

Weathered iron-rich rock, possibly limonite/goethite-bearing material

Limonite (hydrated iron oxides; commonly mixtures of goethite, hematite, and lepidocrocite)

Weathered iron-rich concretion or limonite-bearing rock

Limonite/goethite-rich concretion; limonite is an iron-oxide/hydroxide mixture, commonly dominated by goethite (FeO(OH))

Likely ironstone concretion or weathered iron-rich rock

Goethite/hematite-bearing limonite (FeO(OH)·nH₂O / Fe₂O₃)

Iron-rich weathered rock, possibly limonite/goethite-bearing laterite

Limonite (amorphous hydrated iron oxides), commonly mixed with goethite (α-FeO(OH)) and hematite

Yellow Ochre / Limonite

Limonite (FeO(OH)·nH2O)

Hematite-rich ironstone concretion

Hematite (Fe₂O₃), likely mixed with goethite/limonite and silica

Ironstone (with possible Hematite/Limonite coating)

Ironstone (Fe-rich sedimentary rock)

Specular Hematite

Iron(III) oxide (Fe2O3)

Limonite (Ironstone)

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

Limonite (Ironstone Concretion)

Limonite (FeO(OH)·nH2O)

Iron-oxide-bearing rock fragment

Likely limonite/goethite with quartz or host-rock inclusions; exact identification requires testing

Copper-bearing metamorphic rock, likely bornite- or chalcopyrite-rich schist

Quartz–mica schist with disseminated copper sulfides; possible bornite (Cu₅FeS₄) and chalcopyrite (CuFeS₂)

Hematite

Iron(III) oxide (Fe2O3)

Slag

Anthropogenic glassy silicate

Specular Hematite

Specularite (Fe2O3)

Hematite Pebble

Hematite (Alpha Fe2O3)

Magnetite with Pyrite or Chalcopyrite inclusions

Magnetite (Fe3O4) with Pyrite (FeS2)

Hematite

Iron oxide (Fe2O3)

Weathered ironstone concretion (probable limonite/goethite nodule)

Limonite-goethite-rich iron-oxide concretion; chiefly FeO(OH)·nH₂O

Iron-rich river pebble

Goethite/hematite-bearing, weathered silicate rock (exact identification requires testing)

Likely weathered brown rock or iron-rich mineral specimen

Indeterminate from image; possible limonite/goethite-rich material

Hematite

Iron(III) oxide (Fe2O3)

Tumbled Hematite

Iron(III) oxide (Fe2O3)

Hematite Nodular Iron Ore

Hematite (Fe2O3)

Limonite Concretion

Limonite (Hydrated iron oxide) FeO(OH)·nH2O

Limonite (Ironstone Concretion)

Limonite: FeO(OH)·nH2O

Gossan (with Limonite/Hematite coating)

Ferruginous Gossan (Fe2O3·nH2O / Fe2O3)

Hematite

Iron(III) oxide (Fe2O3)

Goethite

Goethite (FeO(OH))

Iron-rich hematite/goethite concretion (likely limonite)

Hematite (Fe₂O₃) with goethite (FeO(OH)) and limonite

Iron-rich weathered rock, possibly limonite/goethite-bearing ore

Limonite (hydrated iron oxides; chiefly goethite, FeO(OH), with hematite and other oxides possible)

Magnetite

Magnetite (Fe3O4)

Turquoise and Hematite

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