Mineral (Iron Ore)

Tumbled Hematite

Iron(III) oxide (Fe2O3)

Specular hematite (iron ore)

Hematite, Fe₂O₃; likely specularite, possibly mixed with magnetite/goethite

Red Hematite (Banded Iron Formation)

Hematite (Fe2O3)

Hematite

Iron(III) oxide (Fe2O3)

Magnetite with Pyroxene

Magnetite (Fe3O4) in Mafic Igneous Matrix

Polished hematite pebble

Hematite, Fe₂O₃

Pyrite Sun

Iron Sulfide (FeS2)

Iron-rich jasper or weathered hematite fragment

Hematite (Fe₂O₃) in microcrystalline quartz/jasper matrix

Ironstone Concretion / Limonite Specimen

Goethite and Limonite (Hydrous Iron Oxides)

Weathered iron-rich rock, possibly hematite-bearing chert

Hematite (Fe₂O₃), likely mixed with silica and iron oxides

Hematite

Iron(III) oxide (Fe2O3)

Hematite / Jasper

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

Polished hematite

Hematite (Fe₂O₃), likely a tumbled iron-oxide specimen

Likely ironstone or iron-rich rock fragment

Iron-oxide-rich sedimentary material, chiefly hematite (α-Fe₂O₃) and/or goethite (FeO(OH)); exact identification is not possible from the image

Specular Hematite

Hematite (Fe2O3)

Weathered iron-rich concretion or lateritic pebble

Goethite/hematite-bearing ferruginous concretion; composition uncertain from image

Limonite-goethite ironstone specimen

Goethite (α-FeO(OH)) with limonite, quartz, and iron oxides

Hematite

Iron(III) oxide (Fe2O3)

Magnetite (Iron Ore)

Magnetite (Fe3O4)

Specular Hematite (on Schist/Matrix)

Hematite (Alpha-Fe2O3)

Magnetite (potentially Hematite)

Magnetite (Fe₃O₄)

Ferruginous Quartz

Silicon Dioxide (SiO2) with Hematite (Fe2O3) or Limonite (FeO(OH) nH2O)

Probable iron-rich mineral or weathered rock fragment

Indeterminate; possibly limonite/goethite-bearing material

Limonite (Iron Ore)

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

Ironstone Concretion

Siderite or Hematite Concretion

Specular Hematite with Quartz

Ferric oxide (Fe2O3) and Silicon dioxide (SiO2)

Boxwork Siderite or Sepatarian Nodule Weathering

Siderite (FeCO3) with secondary mineralization or Boxwork Geode fragment

Banded Iron Formation (BIF)

Banded Iron Formation

Likely tumbled hematite or hematite-rich ironstone

Hematite (Fe₂O₃), possibly magnetite-bearing ironstone

Botryoidal hematite (iron-oxide specimen)

Hematite, Fe₂O₃; possibly mixed with goethite/limonite

Botryoidal limonite/goethite nodule

Limonite (largely goethite, FeO(OH), with hydrated iron oxides)

Limonite (Yellow Ochre)

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

Polished Hematite Tower

Hematite (Fe2O3)

Limonite / Ironstone

Hydrated Iron Oxide (FeO(OH)·nH2O)

Likely ironstone pebble

Iron-oxide-rich concretion, composed mainly of goethite and/or hematite

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.

Hematite

Iron Oxide (Fe2O3)

Hematite

Iron(III) oxide (Fe2O3)

Pyrite in Matrix (often with Chalcopyrite)

Iron Sulfide (FeS2) / Copper Iron Sulfide (CuFeS2)

Iron Ore (Hematite/Goethite)

Ironstone (Fe2O3 / FeO(OH))

Hematite

Hematite (Fe2O3)

Ferruginous Quartz (Iron-stained Quartz)

Quartz with Iron Oxide inclusions (SiO2 with Fe2O3)