Mineral (Iron Ore)

Hematite

Iron(III) oxide (Fe2O3)

Bornite (Peacock Ore)

Bornite (Copper iron sulfide - Cu5FeS4)

Iron-rich weathered rock fragment

Indeterminate; likely limonite/goethite-bearing sandstone or lateritic ironstone

Iron-rich sandstone or ironstone fragments

Ferruginous sandstone; chiefly quartz (SiO₂) cemented or stained by iron oxides such as hematite (Fe₂O₃) and goethite (FeO(OH))

Weathered iron-rich stone, possibly hematite-bearing basalt or ironstone

Indeterminate; likely Fe-oxide-rich basalt/ironstone, dominated by hematite (Fe₂O₃) and/or magnetite (Fe₃O₄)

Yellow Ocher / Limonite

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

Limonite (Ironstone)

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

Copper Ore (with Malachite/Chrysocolla and Iron Oxides)

Secondary Copper Minerals (Cu2(CO3)(OH)2 / (Cu,Al)2H2Si2O5(OH)4·nH2O)

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Ferruginous Sandstone (River Pebble)

Clastic Sedimentary Rock (Iron-rich)

Hematite (Botryoidal)

Hematite (Fe2O3)

Hematite

Hematite (Fe2O3)

Ironstone Concretion

Siderite or Hematite Concretion (FeCO3 or Fe2O3)

Hematite

Hematite (Fe2O3)

Ironstone concretion

Iron-oxide-cemented sediment, commonly goethite (FeO(OH)) and hematite (Fe₂O₃)

Quartz Vein in Metamorphic Rock

Quartz-veined Schist or Gneiss

Iron-stained quartz-rich rock

Likely quartz with iron oxides/hydroxides (goethite and/or limonite); exact rock type cannot be determined from the image

Hematite (specular hematite/massive hematite)

Hematite, iron(III) oxide (Fe₂O₃)

Hematite

Iron(III) oxide (Fe2O3)

Magnetite (lodestone), possibly meteoritic iron

Magnetite, Fe₃O₄; exact identification is uncertain from the image alone

Hematite (Iron Ore)

Hematite (Fe2O3)

Weathered iron-rich pebble

Likely limonite/goethite-bearing rock; exact identification requires testing

Magnetite (Octahedral Crystal)

Magnetite (Fe3O4)

Limonite

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

Hematite

Iron Oxide (Fe2O3)

Gossan (Iron Hat)

Gossan (secondary iron oxide cap)

Weathered iron-rich rock, likely limonite-bearing sandstone or laterite

Limonite/goethite-rich ferruginous rock; composition commonly FeO(OH)·nH₂O with quartz and clay minerals

Specular Hematite (Specularite)

Iron(III) oxide (Fe2O3)

Rounded ironstone concretion

Iron-rich sedimentary concretion, commonly composed of goethite and/or hematite cementing sand or clay

Specular Hematite (Iron Ore)

Hematite (Alpha-Fe2O3)

Iron-rich laterite or weathered ironstone

Ferricrete/limonite-rich ironstone; primarily goethite (FeO(OH)) and hematite (Fe₂O₃), with clay minerals

Pyrite

Iron sulfide (FeS2)

Ironstone Concretion

Siderite or Hematite-rich Concretion (FeCO3 / Fe2O3)

Galena with Pyrite

Lead Sulfide (PbS) associated with Iron Sulfide (FeS2)

Ferruginous Sandstone

Arenite with Iron Oxide cement (primarily Fe2O3)

Magnetite-rich Iron Ore

Magnetite (Fe3O4)

Ferruginous Sandstone

Ferruginous Sandstone (Quartz Arenite with Iron Oxide cement)

Limonite Concretion

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

Iron-stained quartz-rich metamorphic rock (probable quartzite or hydrothermal vein rock)

Quartz-dominant rock; chiefly SiO₂, with iron oxides/hydroxides and minor sulfide minerals

Specular Hematite (Specularite)

Iron Oxide (Fe2O3)

Magnetite-rich ironstone (probable magnetite ore)

Magnetite, Fe₃O₄, likely in a fine-grained ironstone matrix

Ironstone concretion

Iron-oxide-cemented sediment, chiefly goethite (α-FeO(OH)) and/or hematite (Fe₂O₃)