Mineral (Refined Metal)

Gold

Native Gold (Au)

Gold Nugget

Native Gold (Au)

Gold Grain

Native Gold (Au)

Specular Hematite (Iron Ore)

Iron(III) oxide (Fe2O3)

Gold Nugget

Native Gold (Au)

Blue Goldstone

Man-made glass with crystalline copper/cobalt inclusions

Gold-bearing Quartz

Native Gold (Au) in Quartz (SiO2) matrix

Hematite

Hematite (Α-Fe2O3)

Gold in Matrix

Native Gold (Au)

Turquoise and Hematite

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

Hematite

Iron(III) oxide (Fe2O3)

Cupronickel (on a 1981 Mexico 20 Pesos coin)

Copper-Nickel Alloy (Cu75Ni25)

Bauxite

Bauxite (Mixture of Al(OH)3, AlO(OH), and Fe2O3)

Hematite Nodules (Moqui Marbles style)

Iron Oxide (Fe2O3)

Chalcopyrite

Chalcopyrite (CuFeS2)

Limonite (Iron Ore)

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

Desert Varnish on Sandstone

Quartz Arenite with Iron-Manganese Oxide Coating

Magnetic Sand Grain / Magnetite Pellet

Magnetite (Fe3O4)

Pyrite

Iron Disulfide (FeS2)

Pyrite

Iron Sulfide (FeS2)

Pyrite in Quartz

Iron Sulfide (FeS2) embedded in Silicon Dioxide (SiO2)

Sandstone

Arenite (SiO2 principal)

Green Aventurine

Quartz (SiO2) with fuchsite inclusions

Hematite

Iron(III) oxide (Fe2O3)

Lapis Lazuli (Low-grade/Calcite-heavy)

Na8[Al6Si6O24]n(S,Cl,SO4,OH)2 (Lazurite component)

Hematite Nodule

Hematite (Alpha Fe2O3)

Hematite

Iron (III) Oxide (Fe2O3)

Pyrite

Iron Sulfide (FeS2)

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Quartz with Sulfide Inclusions

Silicon Dioxide (SiO2) with metallic mineral inclusions

Pyrite

Iron Sulfide (FeS2)

Chalcopyrite (Peacock Ore)

Chalcopyrite (CuFeS2)

Magnetite / Hematite mix

Magnetite (Fe3O4) and Hematite (Fe2O3)

Hematite

Iron oxide (Fe2O3)

Hematite

Iron(III) oxide (Fe2O3)

Pyrite

Iron Disulfide (FeS2)

Copper-Bearing Sulfide Ore (likely Chalcopyrite or Bornite)

Chalcopyrite (CuFeS2) or Bornite (Cu5FeS4) in host rock

Red Jasper and Hematite

Silicon Dioxide (SiO2) and Iron Oxide (Fe2O3)

Pyrite (Tumbled)

Iron Disulfide (FeS2)

Hematite

Iron(III) oxide (Fe2O3)

Hematite

Iron(III) oxide (Fe2O3)

Rough Black Diamond (Bort / Carbonado)

Diamond (C)