Mineral, Specifically An Iron Ore

Banded iron formation fragment

BIF: microcrystalline quartz (chert/jasper) with iron oxides and/or magnetite

Green Sandstone

Glauconitic Sandstone

Banded iron formation (iron-rich jasper/chert)

Banded iron formation, chiefly quartz (SiO₂) with hematite, magnetite, and/or goethite (Fe oxides/hydroxides)

Hematite (likely Botryoidal or Specularite variant)

Iron(III) oxide (Fe2O3)

Limonite (Iron Stone/Gossen)

Limonite (FeO(OH)·nH2O)

Yellow Quartz (Citrinated Quartz)

Silicon Dioxide (SiO2)

Lake Superior Agate

Silicon Dioxide (SiO2) - variety: banded chalcedony quartzite

Basalt River Stone

Basalt (Mafic volcanic rock, primarily Plagioclase and Pyroxene)

Red Jasper

Silicon Dioxide (SiO2) with Hematite impurities

Gold Ore

Auriferous Quartz and Sulfide Mineralization in Host Rock

Magnetite / Iron-Rich Basalt

Magnetite bearing Mafic Rock (Fe3O4)

Hematite

Iron(III) oxide (Fe2O3)

Limonite (Iron Ore)

Limonite (FeO(OH)·nH2O)

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2)

Carnelian

Carnelian (Silicon Dioxide, SiO2)

Amethyst

SiO2 (Silicon Dioxide with Iron impurities and natural radiation influence)

Iron-rich quartz rock, possibly hematite/goethite-bearing quartz

Quartz (SiO₂) with iron oxides/hydroxides, chiefly hematite (Fe₂O₃) and goethite (FeO(OH))

Likely weathered iron-rich rock (possible limonite/goethite-bearing stone)

Limonite–goethite mixture, commonly approximated as hydrated iron oxides (FeO(OH)·nH₂O)

Yellow Ochre / Limonite

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

Raw Green Jasper

Silicon Dioxide (SiO2) with iron silicate inclusions

Weathered iron-rich rock fragment

Likely limonite/goethite-rich ironstone; exact identification requires testing

Iron-oxide-rich breccia or weathered ironstone

Hematite–goethite ironstone, likely brecciated and quartz-bearing

Gossan (with secondary copper minerals)

Iron-rich oxidized rock cap (Limonite/Goethite with Malachite/Chrysocolla inclusions)

Basalt

Basalt (composition predominately plagioclase feldspar and pyroxene)

Chalcopyrite

Copper iron sulfide (CuFeS2)

Chalcopyrite (Peacock Ore)

Copper Iron Sulfide (CuFeS2)

Chert (specifically Flint or Jasperoid)

Silicon Dioxide (SiO2)

Ferruginous Sandstone

Sandstone (arenite) with Limonite/Goethite cement

Limonite Geode (Ironstone Concretion)

FeO(OH)·nH2O (Hydrated Iron Oxide)

Rhodonite

(Mn,Fe,Mg,Ca)SiO3

Dream Amethyst (Chevron Amethyst)

Silicon Dioxide (SiO2) with iron impurities and gamma radiation exposure

Sandstone (Ferruginous)

Arenite (Fe-rich)

Gossan / Iron-Rich Weathered Rock

Hydrated Iron Oxides / Limonite / Goethite

Limonite with Iron Inclusions

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

Hypersthene

Hypersthene ((Mg,Fe)SiO₃)

Limonite (Ironstone)

Limonite (FeO(OH)·nH2O)

Limonite (Iron Ore Congcretion)

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

Magnetite / Iron Ore

Magnetite (Fe3O4)

Sandstone (specifically Flagstone)

Arenite (primarily composed of SiO2)

Hematite

Hematite (Fe2O3)

Banded Agate (specifically Carnelian Agate)

Silicon Dioxide (SiO2)

Red Jasper and Mookaite Jasper

Silicon Dioxide (SiO2) with Iron Oxide inclusions