Mineral (Refined Metal)

Hematite (Tumbled)

Iron(III) oxide (Fe2O3)

Specular Hematite

Specularite (Iron Oxide, Fe2O3)

Magnetite / Ironstone

Magnetite (Fe3O4)

Gold Nugget

Native Gold (Au)

Ironstone (likely siderite or goethite-rich siltstone)

Ferruginous Siltstone

Chert (Jasper/Flint variety)

Microcrystalline Quartz (SiO2)

Lapis Lazuli

Lapis Lazuli (Primary mineral: Lazurite (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)

Mica Schist

Schist (primarily Muscovite and Biotite mica)

Gold Ore in Quartz

Auriferous Quartz (Gold: Au; Quartz: SiO2)

Barite Rose on Marcasite

Barium Sulfate (BaSO4) on Iron Sulfide (FeS2)

Pyrite

Iron Sulfide (FeS2)

Black Tourmaline (Schorl)

Schorl (Sodium Iron Aluminum Borosilicate Hydroxide), NaFe2+3Al6Si6O18(BO3)3(OH)3OH

Black Tourmaline

Schorl (Sodium Iron Aluminum Borosilicate Hydroxide)

Gold Nugget

Native Gold (Au)

Hematite

Iron(III) oxide (Fe2O3)

Arfvedsonite in Matrix

Arfvedsonite [Na3(Fe2+)4Fe3+Si8O22(OH)2]

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Specularite (Specular Hematite)

Iron Oxide (Fe2O3)

Hematite

Iron(III) oxide (Fe2O3)

Pyrite (on Quartz/Sulfide matrix)

Iron Sulfide (FeS2)

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Shungite

Shungite (carbon-rich Precambrian mineraloid)

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Native Gold (in the form of jewelry)

Gold (Au)

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Chondrite Meteorite

Ordinary Chondrite (L or H Type)

Limonite (Pseudomorph after Pyrite/Marcasite)

Hydrated Iron Oxide (FeO(OH)·nH2O)

Black Pearl (Tahitian Pearl)

Aragonite / Calcite (CaCO3) with Conchiolin

Gold Nugget

Native Gold (Au)

Pyrite

Iron Disulfide (FeS2)

Pyrite

Iron Disulfide (FeS2)

Specular Hematite (Specularite)

Iron Oxide (Fe2O3)

Silicon Carbide (Carborundum)

Silicon Carbide (SiC)

Iron-Nickel Meteorite fragment

Siderite (meteoritic iron), composed primarily of Kamacite (α-(Fe,Ni)) and Taenite (γ-(Fe,Ni))

Specular Hematite (Specularite)

Iron Oxide (Fe2O3)

Pyrite

Iron Sulfide (FeS2)

Gold

Gold (Native Au)

Limonite (Bog Iron)

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

Gold Nugget

Native Gold (Au)

Sandstone with Manganese Dendrites/Oxide coatings

Arenite with Pyrolusite and Romanechite (MnO2)

Basalt with Iron Oxides

Mafic Igneous Rock (Mafite)

Lapis Lazuli

Lapis lazuli (Mainly Lazurite: Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)