Mineral, Specifically An Iron Ore

Specular Hematite

Hematite (Fe2O3)

Orange Calcite

Calcium Carbonate (CaCO3)

Ironstone (iron-oxide-rich rock)

Ironstone, composed mainly of hematite (Fe₂O₃) and/or goethite (FeO(OH)); exact minerals cannot be confirmed visually

Hematite pseudomorph after a fossil or mineralized object (likely iron-oxide concretion)

Hematite, Fe₂O₃, possibly limonite/goethite-bearing

Limonite (Iron Ore)

Limonite (unstructured hydrated iron(III) oxide-hydroxides, often FeO(OH)·nH2O)

Likely magnetite-rich rock (lodestone)

Magnetite, Fe₃O₄, possibly in a fine-grained host rock

Jasper (Yellow Jasper)

Silicon Dioxide (SiO2) with iron inclusions

Sardonyx Cameo

Silicon Dioxide (SiO2) - variety Cryptocrystalline Quartz

Hematite

Iron(III) oxide (Fe2O3)

Chert (Jasper)

Microcrystalline Quartz (SiO2)

Hematite Nodules (Moqui Marbles or similar)

Iron oxide (Fe2O3)

Yellow Aventurine

Quartz (SiO2) with iron-bearing inclusions

Yellow Jasper

Silicon dioxide (SiO2)

Limonite (Iron Ore)

Hydrous Iron Oxide (goethite, lepidocrocite)

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Pyrite-bearing sulfide specimen

Pyrite (FeS₂), possibly with chalcopyrite (CuFeS₂) and/or marcasite

Hematite

Hematite (Fe2O3)

Turquoise color-bead and Hematite necklace

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

Limonite (Iron Ore)

Limonite (mixed iron hydroxides, primarily FeO(OH)·nH2O)

Iron-stained breccia or weathered ironstone

Ferruginous breccia; predominantly quartz/chert fragments cemented by iron oxides (goethite and hematite)

Iron-rich concretion or weathered ironstone

Limonite/goethite-rich iron oxide aggregate, commonly approximated as FeO(OH)·nH₂O

Limonite (Iron Ore)

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

Iron-rich weathered pebble (likely limonite/goethite-bearing rock)

Limonite mixture, commonly dominated by goethite (FeO(OH)) and hematite (Fe₂O₃)

Brown iron-rich rock, likely limonite/goethite-bearing stone

Limonite (hydrated iron oxides; commonly goethite, FeO(OH), with hematite)

Rose Quartz

Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese

Yellow Quartz (Citrine or Iron-Stained Quartz)

Silicon Dioxide (SiO2)

Hematite

Hematite (Fe2O3)

Weathered iron-rich sandstone or ferruginous quartzite

Quartz-rich sandstone, variably cemented by iron oxides (SiO₂ with hematite/goethite)

Limonite (Iron Ore)

Limonite (FeO(OH)·nH2O)

Magnetite-rich iron ore

Magnetite (Fe₃O₄), possibly massive magnetite/ironstone

Copper Ore (Malachite and Limonite bearing rock)

Copper-bearing rock with secondary copper minerals

Pyrite (Iron Pyrites)

Iron Sulfide (FeS2)

Likely iron-rich rock or meteorite fragment

Indeterminate; possible hematite-/magnetite-bearing material

Milky Quartz with Iron Inclusions

Silicon Dioxide (SiO2)

Limonite (Ironstone Concretion)

Limonite (Hydrous ferric oxide mixture, FeO(OH)·nH2O)

Rounded iron-rich pebble

Likely ironstone or ferruginous quartzite; exact identification requires testing

Polished blue-green metallic mineral specimen, likely bornite (“peacock ore”)

Bornite, Cu₅FeS₄; possibly chalcopyrite, CuFeS₂, with iridescent tarnish

Limonite Sandstone

Ferruginous Sandstone (Hydrated Iron Oxide)

Rounded iron-rich pebble, possibly weathered laterite or ironstone

Ironstone/lateritic ferricrete; predominantly goethite–hematite with clay and quartz impurities

Tourmalinated Quartz

Silicon Dioxide (SiO2) with inclusions of Schorl (NaFe2+3Al6Si6O18(BO3)3(OH)3OH)

Montana Moss Agate

Chalcedony (Silicon Dioxide, SiO2)

Rose Quartz

Silicon dioxide with traces of titanium, iron, or manganese (SiO2)